Weathertalk for January 2, 1998 Topic

WeatherTalk for January 2, 1998

Topic: Preliminary Climate Summary for December 1997

The most striking characteristic of December was mild temperatures. Most northern Minnesota counties experienced one of the warmest five Decembers this century and the warmest since 1923 for some communities. Central and southern counties recorded one of the warmest ten Decembers this century. For some communities it was the warmest since 1965, while for others it was the warmest since December of 1959. MSP airport did not record a single day with below normal temperatures until the last day of the month. Precipitation was less than normal for most Minnesota communities, with snow cover well below normal. Total snowfall for the month ranged from 3 to 8 inches, again well below normal.

Topic: A Brief History of Snow Shoveling

Bernard Mergen in his recent book, Snow in America recounts the history of the snow shovel. As early as 1870, a patent was granted to William Wentworth of Seneca Falls, NY for a snow shovel with a riveted metal tip for scrapping. In 1889 a Lydia Fairweather applied for a patent on a snow shovel that had both attachable scrapper and scooper. The snow scooper, sometimes called a yooper scooper, is a large bucket shaped shovel with sides. It is a common snow removal device in the Upper Peninsula of Michigan and in Maine, where 100 to 200 inches of snow occurs most winters.

The first plastic snow shovel patent was granted to a Robert Smith of New Jersey in 1939. These are by far the most popular sold today, many with metal tips for scrapping. In the past three decades, snowblowers and snow throwers have replaced the use of snow shovels for many areas of the country. As a result perhaps the number of heart attacks has been reduced, but on the other hand there are still the occasional serious accidents with these snow removal machines.

Almanac Segment:

Twin Cities Almanac for January 2nd:

The average MSP high temperature for this date is 22 degrees F (plus or minus 12 degrees standard deviation), while the average low is 5 degrees F (plus or minus 12 degrees standard deviation).

MSP Local Records for January 2nd:

MSP weather records for this date include: highest daily maximum temperature of 45 degrees F in 1897; lowest daily maximum temperature of -7 degrees F in 1912; lowest daily minimum temperature of -22 degrees F in 1979; highest daily minimum temperature of 31 degrees F in 1992; record precipitation of 0.40 inches in 1937; and record snowfall of 5.0 inches in 1975. There have been 19 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 19 inches in 1969 and 1970. The worst windchill conditions on this date occurred in 1920, 1928, and 1979 when -50 to -55 degree F readings prevailed during the morning hours.

Average dew point for January 2nd is 8 degrees F, with a maximum of 33 degrees F and a minimum of -31 degrees F.

All-time state records for January 2nd:

Scanning the state climatic data base: the all-time high for this date is 52 degrees F at Canby (Yellow Medicine County) in 1944; the all-time low is -50 degrees F at Pokegama Dam (Itasca County) in 1904.

Words of the Week: Sugar, Mashed Potato, Powder, White Asphalt

These terms are used by skiers to refer to different types of snow. Each term infers the skiability of slope conditions. Sugar snow is composed of crumbly ice crystals, while mashed potato snow is dense heavy snow so thick a shovel will stand up in it. I think sugar snow is relatively better for skiers. Powder snow is the dry, cold powdery mix of ice crystals which Alpine skiers love. Though an ideal mix, it does not typically last very long, crusting or compressing as it ages. White asphalt is the subsurface, compacted layer which rests several inches to several feet underneath the powder or sugar snow on the surface.

Forecast for Jan 3-9:

Snow is a good possibility for most Minnesota communities this weekend, perhaps lingering even into Monday for eastern sections. Temperatures will be closer to seasonal normals during the coming week unlike the relatively warm temperatures recorded during most of December. Another chance for snow across the state by the middle of the next week with overnight temperatures likely to dip below zero. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Friday, Jan 9, 1998

The following will be posted on the WeatherTalk web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Three Cheers for the El Nino Southern Oscilliation (ENSO)

Studies have shown that there is a higher than normal frequency of warm winters in Minnesota during El Nino Southern Oscilliation episodes. Despite the strong 1997 ENSO, this pattern was not evident in November, which was much colder than normal. The ENSO effect did materialize in December, which turned out to be one of the warmest in recent decades. In contrast to those who have been complaining about the warmth and lack of snow cover inhibiting outdoor recreational activities, general contractors and those in the construction industry have been quite pleased to be able to carry on outdoor work. Perhaps more significantly, everyone's pocket book benefitted from lowered heating costs, as Heating Degree Days were 20 to 25 percent less than normal during December.

MPR listener question: In recent years which part of the state has received the most seasonal snowfall and which part the least?

Since climate observations began at the Wolf Ridge Environmental Learning Center (Lake County) in the early 1990s, their records show an average winter snowfall of nearly 115 inches. Should this average continue, it would establish a new record normal snowfall for Minnesota's climate history. The existing record normal snowfall is 107.4 inches at Pigeon River (Cook County) from 1931-1950.

Angus in northwestern Minnesota (Polk County) holds the record normal for the least seasonal snowfall at 27 inches, their average for the period from 1904-1960. Tyler in southwestern Minnesota (Lincoln County) has recorded an average winter snowfall of only 29 inches in recent years. So, should they have a few more dry winters, they may approach the record established at Angus.

Twin Cities Almanac for January 9th:

The average MSP high temperature for this date is 22 degrees F (plus or minus 14 degrees standard deviation), while the average low is 5 degrees F (plus or minus 14 degrees standard deviation).

MSP Local Records for January 9th:

MSP weather records for this date include: highest daily maximum temperature of 45 degrees F in 1939; lowest daily maximum temperature of -11 degrees F in 1977; lowest daily minimum temperature of -32 degrees F in 1977; highest daily minimum temperature of 31 degrees F in 1939; record precipitation of 0.31 inches in 1924; and record snowfall of 3.8 inches in 1924. There have been 9 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 19 inches in 1969. The worst windchill conditions on this date occurred in 1912 and 1982 when -70 to -75 degree F values were prevalent throughout parts of the day.

Average dew point for January 9th is 3 degrees F, with a maximum of 32 degrees F and a minimum of -40 degrees F.

All-time state records for January 9th:

Scanning the state climatic data base: the all-time high for this date is 57 degrees F at Canby (Yellow Medicine County) in 1958; the all-time low is -49 degrees F at Warroad (Roseau County) in 1930.

Words of the Week: Katabatic and Anabatic Winds

Katabatic winds (taken from the Greek word katabatikos, meaning to go down) are sometimes called gravity winds, drainage winds, mountain winds, or glacier winds. They result when air flows downward from higher positions in the landscape. The air may be channeled through canyons as it flows to lower elevations. This will tend to accelerate the air flow and produce strong winds. Some regional winds such as the foehn (German and Austrian Alps), Chinook (Rocky Mountains) and Santa Ana (Southern California) are dry, warm katabatic winds. On the other hand, glacier winds which flow downslope as well, are very cold winds, some of which produce the world's worst windchill conditions. An example would be the Cape Denison-Commonwealth Bay region of Antarctica, where winds flowing downward from the interior of the continent to the coast may reach 100 to 200 mph, producing windchill conditions well below -100 degrees F.

Anabatic winds (taken from the Greek word anabatikos, meaning to mount) are ascending or upslope winds, often the result of heating along valley slopes. These winds are prevalent in many landscapes with pronounced topography, especially during the daylight hours. Balloonists and pilots of sailplanes often use these winds to maintain or gain altitude. There is even a type of sailplane called an Anabat.

Community Salute: Tyler, MN

This little town of about 1300 residents is located along Highway 14 in Lincoln County, not far from Lake Benton. The climate station was established on July 1, 1916 at the residence of W.F. Hague and represents the only long term climate record in the county. At an elevation of 1735 ft (MSL), it is one of the very few climate stations in southwestern Minnesota located along the west-facing upslope landscape of the Buffalo Ridge.

Some of the climate records at Tyler include: 105 degrees F on 8/15/88; -31 degrees F on 1/15/72; 8.57 inches of rain on 6/17/57; 22 inches of snowfall on 1/29/94; 42 inches of snow cover in early March 1969; and a morning low temperature of 11 degrees F on April 3, 1982 climbing to an afternoon high of 73 degrees F, a rise of 62 degrees F in less than 24 hours.

Outlook:

An abrupt change to below normal temperatures is in store for us. The coldest temperatures of the winter season should prevail through much of the second full week of January. Many overnight below zero readings will occur this weekend and early next week, with some snow showers, especially across northern counties. Strong winds over the weekend and early next week will contribute to some very low windchill values as well. By the middle of next week temperatures should moderate some, but there will also be greater chances for snow, particularly as we approach next weekend.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Friday, Jan 16, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: You reported earlier this winter that soils were frozen only to a depth of 7 to 12 inches. Haven't the recent cold temperatures caused the soil to freeze deeper?

Answer: Quite right! Since January 9th when the colder air invaded the state, the depth of frozen soil has been increasing. Most areas report frozen soil at depths ranging from 12 to 20 inches now. The insulating effect of additional snow cover this week should slow down the progression of the freezing layer into the soil.

Topic: Hasn't it been too cold to snow?

Two significant snowfalls occurred across the state this week, each delivering between 3 and 6 inches of accumulation to many communities. These amounts were surprising to some considering the very cold temperatures which ranged from well below zero to a few degrees above zero during the snowstorm.

As anyone who has ever shoveled snow knows, snow density can vary tremendously. We frequently refer to the density of snow by comparing the depth of snowfall in a column or collector to the depth of water left after it melts. A common rule of thumb is that this ratio of snow depth to water equivalent is typically 10:1, that is ten inches of snowfall equates to 1 inch of liquid precipitation. Quite often this is approximately the case. But sampling from the records of this week's snowfall shows that the ratios ranged from 13:1 up to 24:1 around the state, indicating a very light and fluffy snow.

Snow density to some degree is determined by the temperature of the clouds in which it forms, the air through which it falls and the surface upon which it lands. Relatively higher temperatures usually yield snowfalls that are more dense than those which fall in colder conditions.

Though the capacity of the air to hold water vapor is very much a function of air temperature, there are other factors which may govern the amount of snowfall from an individual storm. The geographic size of the storm and time it takes to pass over the landscape is one important factor. Another is the depth of the saturated air layer aloft in which the ice crystals and snowflakes form, and whether there is enough lift (vertical mixing) to keep the process going. Measurable snowfalls have occurred in Minnesota in temperatures as cold as -30 to -40 degrees F, while in polar regions snowfalls have occurred in temperatures as cold as -60 to -70 degrees F.

Topic: Article about Climate Change in the January Atlantic Monthly

I was asked to comment on the article in this month's Atlantic Monthly magazine, "The Great Climate Flip-flop." It was written by William Calvin, a theroretical neurophysiologist at the University of Washington.

The article discusses the ocean currents in the Atlantic which are responsible for transporting heat to higher latitudes and to what degree these currents might be altered by global warming. Some scientists have associated previous alterations in these currents with the onset of global cooling trends, an effect that is not forecasted by the global climate models used to estimate changes brought on by increasing greenhouse gas emissions. The author offers some interesting speculation on what the impacts of such a scenario might be. Written in a creative and highly provacative style, it makes for some interesting reading.

Twin Cities Almanac for January 16th:

The average MSP high temperature for this date is 21 degrees F (plus or minus 14 degrees standard deviation), while the average low is 4 degrees F (plus or minus 15 degrees standard deviation).

MSP Local Records for January 16th:

MSP weather records for this date include: highest daily maximum temperature of 46 degrees F in 1961; lowest daily maximum temperature of -16 degrees F in 1982; lowest daily minimum temperature of -28 degrees F in 1977; highest daily minimum temperature of 34 degrees F in 1894; record precipitation of 0.63 inches in 1915; and record snowfall of 8.4 inches in 1994. There have been 14 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 18 inches in 1984. The worst windchill conditions on this date occurred in 1982 when -65 to -70 degree F values were prevalent throughout very early in the morning before sunrise.

Average dew point for January 16th is 2 degrees F, with a maximum of 34 degrees F and a minimum of -38 degrees F.

All-time state records for January 16th:

Scanning the state climatic data base: the all-time high for this date is 54 degrees F at New Ulm (Brown County) in 1974; the all-time low is -47 degrees F at Thorhult (Beltrami County) in 1977.

Word of the Week: METAR

This is an acronym for meteorological aviation reports and specifically refers to the international coded reports issued hourly from airport stations. Tailored to the needs of aviation, these reports describe current conditions such as air temperature, dew point, humidity, wind direction, wind speed, altimeter setting, visibility, and cloud ceiling among other items. In coded form they are difficult for the general public to read and interpret. However, in recent years many sites on the Internet make them available in decoded form, and in real-time. Some of these web sites are.... http://www.nws.noaa.gov (National Weather Service Home Page) http://iwin.nws.noaa.gov/iwin/mn/mn.html (Minnesota Interactive Weather Information Network) http://www.crh.noaa.gov/mpx/mpxnew.html (National Weather Service Forecast Office in Chanhassen, MN)

Outlook:

Snow is a good possibility for this weekend, with rising temperatures. Temperatures are expected to rise above seasonal averages and carry over into next week. Not many readings actually above freezing, but highs will be mostly in the 20s with some low 30s next week. Following the weekend snows, we will likely see snow again by the middle of the week. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Friday, Jan 23, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: This winter was quiet and mild until this month. Now it seems that we are receiving measurable snowfalls almost every other day. Is this pattern unusual?

Answer: I will try to answer this question using the January snowfall statistics. The MSP airport data (since 1949) show that the average number of days with measurable snowfall during January is nine. We have already recorded 13 days with measurable snowfall this month and it is only the 23rd day of the month. So yes, we are seeing a higher than normal frequency of days with snowfall, at least based on MSP data. The highest frequency of measurable snowfall during January was in 1975 with 19 snowy days, while the lowest frequency was in 1973 and 1990 with just 3 snowy days.

Topic: Planting Crops in February: An Experiment

In the winter of 1981 many parts of southern Minnesota recorded unusually warm temperatures. In fact, on January 24th of that year, Montevideo (Chippewa County) recorded an afternoon high temperature of 69 degrees F, perhaps the highest temperature ever measured in Minnesota during January. This was followed by a very mild spell in mid February. From February 16th to the 21st, many southwestern Minnesota communities measured temperatures in the low to mid 60s. In addition, the soil was snow-free and thawed. At the seedbed depth, soil temperatures ranged from the 40s to low 50s.

Perhaps in response to a coffee shop conversation that asked "what if" some farmers in the area went out and planted spring wheat that week. This perhaps marks the earliest known planting date ever for wheat in Minnesota. Though some of it germinated by mid March and went on to produce a harvestable crop, I don't think this was regarded as a successful experiment. The agricultural statistics data show a trend toward earlier planting dates for many crops, but the February planting was clearly a one shot deal!

Twin Cities Almanac for January 23rd:

The average MSP high temperature for this date is 22 degrees F (plus or minus 14 degrees standard deviation), while the average low is 4 degrees F (plus or minus 14 degrees standard deviation).

MSP Local Records for January 23rd:

MSP weather records for this date include: highest daily maximum temperature of 53 degrees F in 1942; lowest daily maximum temperature of -16 degrees F in 1936; lowest daily minimum temperature of -31 degrees F in 1935; highest daily minimum temperature of 35 degrees F in 1909; record precipitation of 0.49 inches in 1949; and record snowfall of 5.7 inches in 1949. There have been 13 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 38 inches in 1982. The worst windchill conditions on this date were -65 to -70 degree F values which occurred in 1935, 1936 and 1963.

Average dew point for January 23rd is 6 degrees F, with a maximum of 35 degrees F and a minimum of -42 degrees F.

All-time state records for January 23rd:

Scanning the state climatic data base: the all-time high for this date is 59 degrees F at Marshall (Lyon County) in 1981; the all-time low is -55 degrees F at Warroad (Roseau County) in 1936.

Word of the Week: Singularity

This is a term used by climatologists to describe a highly unusual meteorological condition which tends to occur on or near a specific calendar date much more frequently than pure chance would indicate. This concept has been applied to the January thaw which residents in the NE United States often see in the last week of the month. In Minnesota, this term has been used to describe the very high frequency of clear days that occurs in late September and early October.

Outlook:

Though Saturday appears to be mostly dry around the state, except for the northshore area of Lake Superior, another chance for snow appears for Sunday and Monday. Temperatures are expected to be warmer than normal, but especially so by the middle of next week. Perhaps we will see a thaw period for a few days in parts of the state. To: Perry Finelli, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Friday, Jan 30, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Preliminary January climate summary for Minnesota

Despite frequent snowfalls and a spell of very cold weather in the middle of the month (some -20s and -30s F), most Minnesota communities have reported a January mean temperature ranging from 3 to 8 degrees F warmer than normal. This is perhaps attributable to El Nino and more specifically to the persistent cloudiness which kept overnight temperatures rather high on many nights.

Precipitation for January was generally above normal except for some far northern counties. Snowfalls were quite frequent in many places. Many communities reported from 13 to 18 days with measurable snowfalls, and monthly total snowfalls over 15 inches. MSP airport reported over 20 inches and Duluth over 30 inches for the month.

Topic: 50th Anniversary of Weatherwise Magazine

This month's edition of Weatherwise magazine marks the 50th year of publication and celebrates with a retrospective of some of their best material. I highly recommend it for those fascinated by the weather and for science teachers who are looking for interesting historical facts and stories to use in the classroom.

Some samples from the material:

Who was America's first storm chaser? Perhaps Benjamin Franklin was. A letter documents his horseback pursuit of a whirlwind (dust devil) on a day in 1775. He also studied and wrote about lightning, tornadoes, and weather disruptions caused by volcanic eruptions.

What was the weather like in Philadelphia, PA on July 4, 1776? Thanks to Thomas Jefferson who bought his first themometer just two days before (for which he paid 3 pounds and 15 shillings), we know the answer. He recorded a temperature on July 4th of 76 degrees F, with cloudy skies and a southwest wind in the afternoon. This is somewhat cooler and more comfortable than normal for Philadelphia in July.

What was the most tragic weather disaster of the 20th century? According to David Ludlum, founding editor of Weatherwise, it was the cyclone that struck East Pakistan on November 12, 1970. It is estimated that between 200,000 and 500,000 people lost their lives.

The web site for Weatherwise magazine is: http://www.heldref.org/ww/ww.html

Twin Cities Almanac for January 30th:

The average MSP high temperature for this date is 21 degrees F (plus or minus 14 degrees standard deviation), while the average low is 2 degrees F (plus or minus 14 degrees standard deviation).

MSP Local Records for January 30th:

MSP weather records for this date include: highest daily maximum temperature of 48 degrees F in 1989; lowest daily maximum temperature of -9 degrees F in 1899; lowest daily minimum temperature of -29 degrees F in 1951; highest daily minimum temperature of 35 degrees F in 1931; record precipitation of 0.37 inches in 1947; and record snowfall of 3.6 inches in 1947. There have been 9 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 24 inches in 1969. The worst windchill conditions on this date were -60 to -65 degree F values which occurred in 1909 and 1918.

Average dew point for January 30th is 2 degrees F, with a maximum of 32 degrees F and a minimum of -34 degrees F.

All-time state records for January 30th:

Scanning the state climatic data base: the all-time high for this date is 56 degrees F at St Peter (Nicollet County) in 1989; the all-time low is -52 degrees F at Duluth, Leech Lake, and Pokegama Dam in 1899.

Words of the Week: Ice Shove

The word shove taken from the old Middle English word "shouven" is most often used as a verb, meaning to push away or force away. In this context however it is a noun, referring to the slabs of ice pushed upon a shoreline as a result of thermal expansion of lake, sea, or river ice cover, or as a result of strong winds. These sometimes large flat slabs of ice, called pans, may pile up along the shore into odd shaped mounds and towers.

Ice shoves become more evident along the shorelines of larger lakes in Minnesota during late winter and early spring as the temperatures warm up and winds tend to increase in strength. Some good pictures of ice shoves are online at the U.S. Army Corps of Engineers web site: http://www.mvp-wc.usac.army.mil/riverice/photos.html

Outlook:

Looks like cloudy weather for the weekend, with some precipitation statewide on Sunday. Somewhat drier on Monday and Tuesday. But, another low pressure system should bring additional precipitation by the middle of next week. Temperatures will continue to be on the mild side and should warm up even more during the first week of February. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Friday, Feb 6, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: I have heard you remark that both December and January were warmer than normal in the Twin Cities this winter and that each month probably ranks in the top 20 percent warmest historically. This is perhaps due to the effects of the current El Nino episode. But how does the warmth of the two consecutive month period rank in the climatological records?

Answer: Good question! Taken in combination the average MSP temperature for December ('97) and January ('98) this winter is over 23 degree F, compared to a historical average of about 16 degrees F since 1891. This makes the two month combination the 5th warmest in the climatological records. The warmest ever December/January combination occurred in 1913-1914 when the average temperature was over 26 degrees F. This however, was not an El Nino year.

Topic: Mailbox Forecasts

In the early days of the National Weather Service, the morning forecast was distributed by telegraph, sign posted on public buildings, displayed as a series of color coded flags in town squares, or sent by railroad to neighboring communities. Needless to say, without radio or television, getting a weather forecast distributed to the public in a timely way was a considerable problem.

In the late 19th century some federal buildings housed both a local post office and Weather Bureau Forecast Office. During the 1890s in Montgomery, Alabama officials tried the idea of using the postal service to distribute postcards with the days forecast. Weather Service personnel would provide the morning forecast in the form of a coded postcard which they would deliver in quantity to the local post office. Mail carriers would then deliver these postcards to each mailbox on their designated routes, providing most of the citizens with forecast information by 1 pm each day. This was strictly a cooperative agreement between the local postmaster and the chief of the local Weather Service. I could find no record of how long this arrangement lasted, but it was highlighted as a much appreciated service by the citizens of Montgomery, Alabama in an article from the Monthly Weather Review of February, 1899.

Twin Cities Almanac for February 6th:

The average MSP high temperature for this date is 23 degrees F (plus or minus 12 degrees standard deviation), while the average low is 6 degrees F (plus or minus 14 degrees standard deviation).

MSP Local Records for February 6th:

MSP weather records for this date include: highest daily maximum temperature of 51 degrees F in 1925; lowest daily maximum temperature of -13 degrees F in 1936; lowest daily minimum temperature of -24 degrees F in 1936; highest daily minimum temperature of 34 degrees F in 1925; record precipitation of 0.26 inches in 1895; and record snowfall of 5.4 inches in 1946. There have been 7 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 22 inches in 1967 and 1979. The worst windchill conditions on this date were -55 to -60 degree F values which occurred early in the morning in 1936 and again in 1962.

Average dew point for February 6th is 5 degrees F, with a maximum of 38 degrees F and a minimum of -32 degrees F.

All-time state records for February 6th:

Scanning the state climatic data base: the all-time high for this date is 59 degrees F at Madison (Lac Qui Parle County) in 1963; the all-time low is -47 degrees F near Baudette (Lake of the Woods County) in 1967.

Word of the Week: Semaquir

Partially derived from the Greek term sema, meaning sign, the literal translation of this word is "signature stone." In Finland this stone has the reputation as a weather forecasting tool. It is composed of rock salt and sodium nitrate, both of which are hygroscopic (water absorbing material). When they absorb the vapor from very moist air, the surface of the stone becomes dark, and rain is expected. In dry weather, the surface has a mottled dark and white appearance as a result of salt depositions left after evaporation.

Outlook:

The trend of above normal temperatures is expected to continue over the weekend and through next week. A chance for snow or perhaps even freezing drizzle for late Monday through Wednesday of next week, with mostly cloudy skies. Temperatures will reach the 30s and 40s in some places around the state. WeatherTalk for February 13, 1998

Topic: Freeze-Thaw Cycles

In a typical Minnesota winter, we experience several long periods of cold when the temperature never gets above freezing (32 F). Even in the heat island of the Twin Cities, there are between 60 and 70 days each winter when the maximum temperature never reaches 32 degrees F. This has not been the case in the winter of 1997-98, one of the warmest in recent memory. The warm winter has produced a very high frequency of daily freeze/thaw cycles, that is when the temperature has oscillated either side of 32 degrees F. So far the Twin Cities climate record since November 1st shows 50 days in which the daily temperature has ranged either side of 32 degrees F (normal is 35 for the Nov 1 to Feb 12 period). This can be detrimental to paved roads, concrete sidewalks and some building materials. It will be interesting to see if this abnormally high incidence of freeze/thaw cycles is manifested in needed road or building repairs this spring.

Question from Morning Edition Producer Jim Bickal: Why does the overnight minimum temperature often occur just before or at sunrise?

Answer: In the absence of overnight wind and cloud variations the Earth's surface gives up energy by emitting long wave radiation. This process goes on all night long at roughly the same rate and leads to a cooling of the air near the surface. At sunrise or shortly after, the Earth's surface begins to absorb radiation again and convection currents mix and heat the air, thus ending the radiational cooling process. In this context, it is understandable that just before sunrise the lowest air temperatures should occur.

This time of year, the daily temperature range is typically 15 to 20 degrees F. However, two factors can greatly magnify this daily temperature range if they interact in the right combination. Daylength and sun angle are increasing, thus in the absence of daytime clouds and permanent winter snow cover, the Earth's surface can absorb more energy each day. If there is a change in air masses during a 24 hour period (say from warm and moist to dry and cold), this too can greatly magnify the daily temperature range. These factors must have come into play at Tracy, MN (Lyon County) on this date in 1990, when the afternoon high reached 61 degrees F under sunny skies, southerly winds, and with no snow cover. This was followed by the passage of an overnight arctic air mass which brought dry cold air and produced a minumum temperature of 4 degrees F just before sunrise (a 57 degree drop in temperature).

So far this month overnight clouds have kept many of the daily minimum temperatures quite high compared to normal.

Almanac Segment:

Twin Cities Almanac for February 13th:

The average MSP high temperature for this date is 27 degrees F (plus or minus 12 degrees standard deviation), while the average low is 10 degrees F (plus or minus 14 degrees standard deviation).

MSP Local Records for February 13th:

MSP weather records for this date include: highest daily maximum temperature of 50 degrees F in 1921; lowest daily maximum temperature of 0 degrees F in 1905 and 1909; lowest daily minimum temperature of -23 degrees F in 1905; highest daily minimum temperature of 34 degrees F in 1911; record precipitation of 0.60 inches in 1915; and record snowfall of 5.5 inches in 1909. There have been 13 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 22 inches in 1979. The worst windchill conditions on this date were -50 to -55 degree F values which occurred early in the morning in 1905 and again in 1922.

Average dew point for February 13th is 12 degrees F, with a maximum of 36 degrees F and a minimum of -23 degrees F.

All-time state records for February 13th:

Scanning the state climatic data base: the all-time high for this date is 53 degrees F at Mankato (Blue Earth County) in 1990; the all-time low is -46 degrees F at Detroit Lakes (Becker County) in 1916.

Words of the Week: Zenith, Nadir, and the Celestial Sphere

These terms are used by meteorologists, climatologists and other scientists with reference to astronomical positions. They are derived from ancient terms used to refer to heaven and hell. The celestial sphere is the apparent or imaginary sphere, of infinite radius, with the Earth at its center. Thus for any person standing on Earth they can see one half of the celestial sphere when they look from one horizon across the sky overhead to the other horizon.

In this context, directly above the observer is the zenith, or highest point in the heavens. This term is often used in other ways, for example to say that a musician or athlete is at the zenith of their career would mean that they are at peak performance or productivity. Conversely, the nadir refers to a point directly below the observer in the celestial sphere, a exactly opposite from the zenith. This term is also used in other ways to describe when an individual or organization is at an all-time low in terms of performance or productivity.

Forecast for February 14-20:

The warming trend should continue for the weekend and most of next week. It will be moderated by some cloudiness Sunday through Wednesday, with a chance for snow or rain. The low pressure systems affecting Minnesota during those days will also have considerable wind associated with them. Temperatures may be on the order of 10 to 15 degrees above normal during the period.

Monthly and Seasonal Outlooks:

The latest monthly and seasonal outlooks from the Climate Prediction Center, favor warmer than normal temperatures for March, and for the entire March, April, and May period across Minnesota. There are no significant deviations in precipitation expected. Should we follow the current trend of warmth which started in December, this will go down as one of Minnesota's warmest winters. To: Perry Finelli, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Friday, Feb 20, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Warm February

So far this February is proving to be the warmest since 1987 and may turn out to be one of the warmest in history. The eastern Minnesota climate record, dating back to 1820 at Ft Snelling, shows that the average temperature for February has been 32 degrees F (right at the freezing mark) only 5 times in 178 years. Those years were 1877, 1878, 1931, 1954, and 1987. So far this month, the average temperature for MSP airport is over 28 degrees F and still climbing because of the recent trend of warm temperatures. Should the warm trend prevail to the end of the month, it is possible that February of 1998 will approach an average temperature of 32 degrees F as well. This follows an abnormally warm December and January across the state.

The warm temperatures are perhaps triggering some spring-like response from landscape vegetation. This is cause for concern, as some plants that break dormancy, will be more vulnerable to damage from subsequent cold spells in March or April. On the other hand, extension horticulturalists tell us that late February and early March provide good opportunities for pruning shade trees, before they start spring growth. In addition the oscilliating temperature pattern above and below the freezing mark will undoubtedly boost maple sap production this year.

Common questions: This unusual winter warmth has prompted a number of questions from MPR listeners and University of Minnesota Extension Program audiences. Two of the most common are:

Since the unusually warm winter is being attributed to El Nino, based on historical evidence, what weather might we expect for the spring and summer?

There are no correlations between El Nino episodes and Minnesota's spring or summer weather patterns. El Nino episodes do tend to stack the odds in favor of a warmer than normal winter for our state, but they do not stack the odds for any particular type of weather pattern in the spring or summer months.

Regardless of what happens to El Nino, doesn't the unusual winter warmth indicate that we will have a dry spring and summer?

No, again. After examining the twenty-five warmest winters of the past century in Minnesota, there is roughly an equal probability associated with wet or dry spring and summer months. Warm winters apparently do not stack the odds in favor of a dry spring or summer.

Twin Cities Almanac for February 20th:

The average MSP high temperature for this date is 28 degrees F (plus or minus 12 degrees standard deviation), while the average low is 11 degrees F (plus or minus 13 degrees standard deviation).

MSP Local Records for February 20th:

MSP weather records for this date include: highest daily maximum temperature of 57 degrees F in 1981; lowest daily maximum temperature of -4 degrees F in 1918; lowest daily minimum temperature of -18 degrees F in 1918; highest daily minimum temperature of 35 degrees F in 1899; record precipitation of 0.43 inches in 1891; and record snowfall of 4.2 inches in 1979. There have been 12 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 29 inches in 1967. The worst windchill conditions on this date were -55 to -60 degree F values which occurred early in the morning in 1918 and again late at night in 1963.

Average dew point for February 20th is 12 degrees F, with a maximum of 41 degrees F and a minimum of -26 degrees F.

All-time state records for February 20th:

Scanning the state climatic data base: the all-time high for this date is 65 degrees F at Tracy (Lyon County) in 1930 and at Luverne (Rock County) and Canby (Yellow Medicine County) in 1981; the all-time low is -50 degrees F near Baudette (Lake of the Woods County) in 1966.

Words of the Week: The Reseau Mondial

Derived from french terms, the reseau mondial translates literally to mean a "network of observations" for an Earth day. Seeing a need for worldwide weather observations to be both organized and standardized, the International Meteorological Committee proposed the establishment of a worldwide observational network in 1907. Seventeen countries promoted this idea. Their goal was based on using a reseau, or gridded network that covered the entire Earth. Each 10 degree latitude by 10 degree longitude grid was to have at least two meteorological stations, for a total of about 2600 stations worldwide. These stations would all record the same data on a daily basis, including air pressure, temperature, humidity, wind, sky condition, and precipitation among others. Though it has been nearly a century since this idea was proposed, and there are many thousands of manual and automated meteorological stations currently operating under the standards of the World Meteorological Organization, we have still not achieved the idealized spatial coverage of observations described in the reseau mondial. Perhaps with the increased deployment of satellite based meteorological observations, there is no longer the need.

Outlook:

Quiet start to the weekend, with temperatures remaining well above normal and more sunshine than of late. Increasing clouds late in the weekend with a chance for precipitation (rain or snow) beginning Sunday night and extending into the early part of next week. Winds will be stronger next week as two low pressure systems affect the state, bringing unsettled weather nearly each day. Temperatures will remain above normal, but not as much as this past week. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Friday, Feb 27, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: I have heard that we are having a remarkable run of above normal temperatures in the Twin Cities, dating back to January 21st, a period of 37 consecutive days. Is this approaching some kind of a record?

Answer: It depends somewhat on what MSP normal temperatures are used. If we use the current averaging period, 1961 to 1990, then the record for consecutive days with above normal temperatures is 50 set from November 11 to December 28, 1923. The current string of 37 consecutive days would rank 8th longest.

Another marker of the persistence in warm temperatures comes from the percentage of days with above normal mean temperature. Since Thanksgiving, a period of 92 days, many Minnesota communities have reported above normal daily mean temperatures 85 to 90 percent of the time. This is close to a record percentage for this period of the year.

Topic: Fire Weather

Though it may seem odd, the warm winter, general absence of snow cover, and onset of perhaps an early spring have triggered some concern for fire potential. Precipitation deficits were quite large last year in parts of north central and northeastern Minnesota, according to the State Climatology Office. A dry early spring coupled with continued above normal temperatures before the forest and understory vegetation greens up may lead to more rapid dessication of already dry lighter fuels on the forest floor and surrounding landscape. Such conditions would provoke a higher than normal fire danger in this area of the state.

The US Forest Service Wildland Fire Assessment System tracks the fire potential around the country on a daily basis. They use a variety of data and information resources to do so including: daily observations of temperature, humidity, wind and precipitation; satellite derived vegetation indices (called greenness maps), the Keetch-Byram Drought Index, forecasted lightning potential, atmospheric stability (Haines Index), and estimates of dead fuels (downed trees, decaying wooded species, etc). These data, along with fire danger categories and fire weather forecasts are updated each day on the Forest Service Web site: http://www.fs.fed.us/land/wfas

The fire weather monitoring and warning system in the United States is now one of the best in the world, partially the result of renewed and invigorated efforts from state and federal agencies following the tragic fires in Yellowstone Park and other places in the late 1980s.

Twin Cities Almanac for February 27th:

The average MSP high temperature for this date is 30 degrees F (plus or minus 11 degrees standard deviation), while the average low is 14 degrees F (plus or minus 13 degrees standard deviation).

MSP Local Records for February 27th:

MSP weather records for this date include: highest daily maximum temperature of 54 degrees F in 1896; lowest daily maximum temperature of -1 degrees F in 1962; lowest daily minimum temperature of -14 degrees F in 1897; highest daily minimum temperature of 37 degrees F in 1895 and 1983; record precipitation of 1.01 inches in 1981; and record snowfall of 5.5 inches in 1893. There have been 14 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 24 inches in 1962 and 1967. The worst windchill conditions on this date were -50 to -55 degree F values which occurred early in the morning in 1919 and again in 1922.

Average dew point for February 27th is 15 degrees F, with a maximum of 42 degrees F and a minimum of -21 degrees F.

All-time state records for February 27th:

Scanning the state climatic data base: the all-time high for this date is 66 degrees F at Pleasant Mound (Blue Earth County) in 1896; the all-time low is -40 degrees F at Warroad (Roseau County) in 1913.

Word of the Week: Duff

This is an old English term for plum pudding made from a stiff flour mixture. It is also a term often used to describe my golf shots. So how does it relate to meteorology you say? It is an important term in the fire weather program of the U S Forest Service, used to describe the partially decayed organic matter on the forest floor which can become highly combustible during drought periods and contribute to the longevity and spread of forest fires. In fact the Keetch-Byram Drought Index is sometimes referred to as the soil/duff drought index because it is a measure of how dry the soil and duff layers are.

Outlook:

Quite a change in the weather coming up. Minnesota will be affected by persistent low pressure during the weekend and much of next week. A mixture of precipitation (rain and snow) is likely through next Wednesday. Winds will continue to be moderate to strong. Temperatures will decline to seasonal normals, or perhaps even a few degrees colder than normal during the first full week of March.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, March 6, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: How many minutes of daylight are gained during the month of March and how much does the sun angle change?

Answer: Locally, for the Twin Cities, we gain over 1.5 hours in daylength during March. The sun's maximum daily elevation angle above the horizon changes by roughly 11 degrees, from 38 degrees above the horizon at midday on the 1st to 49 degrees above the horizon at midday on the 31st.

Topic: Record or near record setting mean temperatures for February 1998.

Station Mean Feb Temp Historical Ranking Location deg F for period of record

Crookston 26.2 New record, old 25.6 F in 1931 Fargo-Moorhead 28.0 New record, old 27.5 in 1987 Warroad 25.5 New record, old 23.2 in 1954 Grand Rapids 30.0 New record, old 25.4 in 1987 Inter'l Falls 27.2 New record, old 23.5 in 1987 Itasca St Park 28.0 New record, old 25.9 in 1987 Duluth 28.8 3rd warmest, record is 31.4 in 1877 Hibbing 28.5 New record, old 22.9 in 1987 Alexandria 27.6 2nd warmest, record 28.5 in 1987 Canby 31.4 3rd warmest, record is 33.5 in 1954 Montevideo 29.4 3rd warmest, record is 33.6 in 1987 Morris 27.4 4th warmest, record is 29.5 in 1987 St Cloud 29.6 New record, old 28.9 in 1987 Willmar 28.1 4th warmest, record is 30.8 in 1987 Aitkin 28.8 New record, old 24.6 in 1984 Cambridge 29.0 2nd warmest, record is 30.4 in 1987 MSP airport 31.9 2nd warmest, record is 32.0 in 1931 Pipestone 30.2 2nd warmest, record is 32.3 in 1931 Redwood Falls 29.8 3rd warmest, record is 32.3 in 1987 Worthington 30.2 4th warmest, record is 33.9 in 1931 Faribault 30.8 3rd warmest, record is 33.5 in 1954 Waseca 29.6 3rd warmest, record is 33.2 in 1954 Winnebago 29.8 4th warmest, record is 32.8 in 1931 Caledonia 32.2 New record, old 27.9 in 1984 La Crosse, WI 33.7 4th warmest, record is 34.1 in 1877 Rochester 29.4 3rd warmest, record is 31.8 in 1954 Rosemount 30.7 2nd warmest, record is 31.2 in 1987, 1954 Winona 33.2 2nd warmest, record is 33.7 in 1954

February was the third consecutive month with above normal temperatures. Heating bills were again considerably lower for the month, with 30 to 35 percent less than normal heating degree days in northern Minnesota counties, and 28 to 30 percent less than normal in the remainder of the state.

Minnesota's livestock producers were quite happy with the mild February as well. Weight gains and livestock feeding efficiency have been excellent as animals have not had high feed requirements for maintenance against harsh weather as they did last winter. Many have been able to haul and spread manure throughout the winter, though lately with thawing soils it has been too soft and muddy. Bills for heating animal buildings have been less than recent years as well.

The winter months of December, January and February now rank as the second warmest three month spell on a statewide basis, according to the Minnesota State Climatology Office. The statewide average temperature has been 21.9 degree F for the three months and this is exceeded only by December-February of 1877-78 which recorded an average temperature of 26.0 degrees F. March 11 of 1878 was the earliest ever date for the ice on lake Minnetonka to disappear.

Topic: Global Climate Change Models Evolving

According to climatologists from the Illinois State Water Survey, some recent projections from the global climate change models now suggest that the climate of the central US may become cooler and wetter by the year 2050. This does not discount the hypothesis that the entire Earth system will become warmer, but it does suggest that the distribution of climate change will be variable across the northern hemisphere. Climate predictions are changing and evolving as the research models incorporate the effects of variable aerosols in the environment and consider land and ocean feedbacks. They go on to say that climate records of the midwest do not support the hypothesis of an increased frequency in various weather extremes such as thunderstorms, hailstorms, winter storms, or summer heat waves. We will undoubtedly be hearing more about these topics as a larger number of scientists study the temporal and spatial characteristics of climate extremes, and the projected consequences of regional climate changes.

Twin Cities Almanac for March 6th:

The average MSP high temperature for this date is 32 degrees F (plus or minus 11 degrees standard deviation), while the average low is 16 degrees F (plus or minus 12 degrees standard deviation).

MSP Local Records for March 6th:

MSP weather records for this date include: highest daily maximum temperature of 67 degrees F in 1987; lowest daily maximum temperature of 6 degrees F in 1899; lowest daily minimum temperature of -12 degrees F in 1899; highest daily minimum temperature of 44 degrees F in 1983; record precipitation of 0.97 inches in 1983; and record snowfall of 7 inches in 1900. There have been 13 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 24 inches in 1962. The worst windchill conditions on this date were -50 to -55 degree F values which occurred from late morning through most of the afternoon in 1932.

Average dew point for March 6th is 15 degrees F, with a maximum of 54 degrees F and a minimum of -18 degrees F.

All-time state records for March 6th:

Scanning the state climatic data base: the all-time high for this date is 74 degrees F at Madison (Lac Qui Parle County) and at Marshall (Lyon County) in 1987; the all-time low is -41 degrees F at Embarrass (St Louis County) in 1996.

Words of the Week: Scotch mist

To some people this is what you sip while sitting in front of a roaring fireplace in the winter. But my frame of reference is strictly meteorological!

This term has been used for generations to describe a combination of thick mist (or fog) and heavy drizzle in Scotland and parts of England. Droplets vary in size from less than .01 inches in diameter to .02 inches in diameter. Some remain suspended in the atmosphere while others fall to the ground. Visibility is is greatly reduced. In southwestern England, particularly Devon and Cornwall, the same type of weather is referred to as "mizzle" (a combination of mist and drizzle).

Outlook:

Some snow likely for southern portions of the state this weekend, as an intense low pressure system passes to the south. Winds will be increasing. Mostly cloudy in northern sections. Temperatures will be sharply colder around the state on Monday through Wednesday next week, with some below normal readings. A warming trend is likely however by the end of the week, with increasing chances for precipitation.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, March 13, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: February Warmth/March Cold = Troubling Quotient

Three troubling situations have developed as a result of an an arctic air mass descending on the state following a record warm February:

1) Many alfalfa fields broke dormancy during February and actually started to show growth. Having done this, makes these plants more susceptible to cold temperature injury or winterkill. Two or more consecutive nights of below zero and single digit temperatures this week in the absence of protective snow cover have probably inflicted a fair amount of damage on this crop. It remains to be seen how many fields will recover from this, but it could be a setback for hay supplies this year.

2) The record warm February thawed the landscape enough to start the snowmelt runoff into major rivers and streams. Most of the block ice and ice floes disappeared on these rivers, eliminating the threat of ice jams. However the recent cold temperatures have supercooled the water in flowing streams and rivers such that frazil ice (also called needle ice) has started to form. This form of ice is usually found in moving water and may stick to submerged debris or material along the embankment. Ice may also build up in and around water control structures like dam outlets. These ice formations may tend to restrict and slow the flow of water and allow backwater to build up, perhaps causing local flooding.

3) The warm February began to thaw some lakes around the state. As lakes thaw, the ice sheet that covers them develops cracks and water flows up by capillary action to spill over the ice. With the return of cold temperatures everything refreezes, including the open water between the floating ice. As this process is repeated, the ice sheet covering the lake expands horizontally. This is called "ice jacking" because it mimics the same kind of expansion accomplished by a mechanical jack. On lakes with high water levels, the expansion of ice along the shoreline may push away or scour out the soil and lift or crush shoreline vegetation. According to the DNR some of this action has already occurred on various Minnesota lakes.

Topic: The North Atlantic Oscillation/El Nino's cousin

Some people have asked if there is any feature in the Atlantic Ocean which is analagous to El Nino in the Pacific. The closest analogy may be the North Atlantic Oscilliation Index (NAOI) which is based on the pressure difference between the Azores (several hundred miles off the coast of Portugal) and Iceland. When this air pressure difference is positive due to a deepening of the Icelandic low or a strengthening of the Azores high, westerly winds tend to be stronger and much of Europe tends to have a milder winter. Drier conditions also prevail over parts of central and southern Europe with a positive NAOI. Much about the behavior of the NAOI is still unknown, but the oscillating behavior of the pressure pattern is somewhat like that of the El Nino Southern Oscillation in the equatorial Pacific. However, while the pressure oscillation of El Nino is primarily west to east in orientation, that of the NAOI is south to north in orientation.

Twin Cities Almanac for March 13th:

The average MSP high temperature for this date is 36 degrees F (plus or minus 11 degrees standard deviation), while the average low is 21 degrees F (plus or minus 12 degrees standard deviation).

MSP Local Records for March 13th:

MSP weather records for this date include: highest daily maximum temperature of 64 degrees F in 1973; lowest daily maximum temperature of 12 degrees F in 1906; lowest daily minimum temperature of -9 degrees F in 1895; highest daily minimum temperature of 46 degrees F in 1995; record precipitation of 0.69 inches in 1917 and 1986; and record snowfall of 8 inches in 1940. There have been 14 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 27 inches in 1962. The worst windchill conditions on this date were -25 to -30 degree F values which occurred in 1906 and again in 1993.

Average dew point for March 13th is 22 degrees F, with a maximum of 52 degrees F and a minimum of -11 degrees F.

All-time state records for March 13th: Scanning the state climatic data base: the all-time high for this date is 77 degrees F at Mankato (Blue Earth County) in 1990: the all-time low is -36 degrees F at Campbell (Wilkin County) in 1896.

Word of the Week: Chilblains

Taken from old Middle English and Anglo Saxon terms (chill for cold or shiver and blains for sore or swelling) this term refers to a distress of the skin as a result of exposure to cold temperatures. It primarily occurs on exposed hands, wrists, feet or ankles, but sometimes ears, nose or cheeks will show symptoms as well. Aside from some pain, the symptoms are swelling, itching, burning, or a redness or bluish mottled appearance. Sometimes the skin will crack. Not as severe as frostbite, this distress is primarily the result of the contraction in the blood vessels near the surface of the skin. The medical term used for this is acrocyanosis. Perhaps in reaction to the arctic air mass this week, some Minnesotans who failed to bundle up properly are suffering from chilblains.

Outlook:

A gradual warming trend through the weekend and into next week is likely. A chance for snow, especially up north over the weekend. Temperatures will climb into the mid 30s to mid 40s next week, with another chance for precipitation, perhaps rain, by Wednesday or Thursday. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, March 20, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: Don't we normally see more sunshine as we get closer to spring in Minnesota? Doesn't our average percent possible sunshine increase?

Answer: Yes, historical data show that November and December are the two cloudiest months in Minnesota with averages of only 39 and 40 percent possible sunshine, respectively. Then each succeeding month shows an increase in percent possible sunshine, which averages 55-60 percent during March. This has certainly not been the case this winter.

Topic: New Monthly and Seasonal Outlooks

The NOAA Climate Prediction Center just released the new monthly and seasonal temperature and precipitation outlooks. For April, no significant deviations in temperature or precipitation are seen for Minnesota, suggesting near normal conditions. For the April through June period, temperatures are expected to average near normal, while precipitation is expected to be somewhat less than normal across the entire Great Lakes region, including Minnesota.

Topic: Detective Meteorology

In the current issue of Weatherwise magazine (Mar-Apr), there is an interesting article by Lee Grenci about how satellite meteorologists observed an odd cloud formation over southern Greenland last December (1997). It turns out that what they observed was a relatively warm impact cloud of water droplets and ice crystals that resulted from the impact of a large meteorite on December 9th. No estimates for the size of the meteorite are given, but the impact cloud was 4-5 miles high and over 74 miles across.

Topic: Preliminary Tornado Data for 1997

The Storm Prediction Center in Norman, OK has reported preliminary tornado statistics for 1997. There were 967 tornadoes reported in the United States, the fewest since 1989. Sixty-nine deaths were attributed to tornadoes. The most deadly tornado, an F5, struck Jarrell, TX on May 27th, killing 27 people. Texas reported the most tornadoes with 135, followed by Florida with 70, Kansas with 61, Oklahoma with 50, and Minnesota with 45. It is unusual for Minnesota to rank 5th among states in the number of tornadoes and the number reported for 1997 is over twice as many as the historical average.

Twin Cities Almanac for March 20th:

The average MSP high temperature for this date is 41 degrees F (plus or minus 12 degrees standard deviation), while the average low is 23 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for March 20th:

MSP weather records for this date include: highest daily maximum temperature of 66 degrees F in 1938; lowest daily maximum temperature of 12 degrees F in 1951; lowest daily minimum temperature of -9 degrees F in 1965; highest daily minimum temperature of 41 degrees F in 1938; record precipitation of 0.86 inches in 1921; and record snowfall of 3.8 inches in 1901. There have been 9 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth for this date was 25 inches in 1951. The worst windchill conditions on this date were -30 to -35 degree F values which occurred in 1951.

Average dew point for March 20th is 22 degrees F, with a maximum of 51 degrees F and a minimum of -12 degrees F.

All-time state records for March 20th:

Scanning the state climatic data base: the all-time high for this date is 76 degrees F at Winnebago (Faribault County) in 1910: the all-time low is -37 degrees F at Big Fork (Itasca County) in 1965.

Words of the Week: Ekman spiral

Named for Swedish physicist Walfrid Ekman (1874-1954) the Ekman spiral is an idealized mathematical representation of how the wind driven surface currents of the ocean behave with depth; and also a representation of how wind speed and direction vary with height above the ground.

In the oceans of the northern hemisphere, wind driven surface currents spiral to the right with depth as a result of friction and the Coriolis force (rotation of the Earth). This motion traces an imaginary clockwise descending spiral.

In the atmosphere, the Ekman spiral refers to how winds spiral to the right with height above the ground, as a result of the balance between the Coriolis, pressure gradient, and friction forces. This motion traces an imaginary clockwise ascending spiral. Thus a wind from the south (180 degrees) at the ground level may become a stronger wind from the southwest (225 degrees) at a height of 1000 meters.

The clockwise drift of winds and ocean currents in the northern hemisphere, becomes a counterclockwise drift in the southern hemisphere as a result of the Coriolis force.

Outlook:

Partly cloudy Saturday, but mostly dry. Then increasing cloudiness for Sunday and Monday with a chance for snow. Temperatures will be a few degrees colder than normal, but then warm up next week to near normal or above. Stronger southerly winds may push temperatures into the 40s and 50s by the end of the week, but will also bring a chance for precipitation for Wednesday through Friday. To: Perry Finelli, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, March 27, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: Did the weather have anything to do with the sinking of the Titanic?

Answer: Not directly, but the Monthly Weather Reviews for 1912 emphasize a very cold period from January through March over the North Atlantic states, calling it "one of the most remarkable cold spells experienced...for a third of a century." Indeed, some record setting cold weather dominated much of the northern hemisphere during the winter months of 1912. The effects of this cold spell may have contributed to the perservance of the 70 mile long ice field which had to be negotiated along the North Atlantic shipping channel during April. It was within this area that the Titanic encountered a deadly iceberg. Today's technology, with satellite microwave sensors monitoring the oceans for sea ice, provides ship's captains with infinitely better guidance and information for safely navigating through troubled waters.

Topic: Dave Barry's Analysis of El Nino

Everyone has been talking about El Nino this winter, prompting syndicated columnist Dave Barry to take a turn at it in this month's Weatherwise magazine. Among his interpretations: accelerated evaporation loss from the oceans is caused by too many whales surfacing and blowing their noses; the atmosphere is probably getting warmer anyway as a result of too much steam from espresso machines and too many people smoking cigars; and the Army Corps of Engineers should never have constructed the jet stream to bring these storms across the United States. He also describes an interesting recipe for a bathtub demonstration of El Nino.

Topic: The Sun's Impact on the Climate of Earth

Recent presentations at the American Association for the Advancement of Science annual meeting offer some interesting hypotheses about the sun. Scientists at the Naval Research Laboratory report that the sun has been growing increasingly brighter, albeit only by a very small fraction (perhaps less than 0.1 percent over the past 400 years). They contend that this may have caused some of the global warming observed this century. A researcher from Imperial College in London who models ozone in the stratosphere suggests that absorption of ultraviolet radiation warms that level of the atmosphere. During times of relatively higher uv radiation from the sun, additional ozone is produced as more ordinary oxygen molecules in the stratosphere are split up and then recombine to form the ozone molecule. More uv radiation is absorbed by this ozone and the heat is translated to the lower atmosphere by natural circulation patterns. Lastly, other scientists from the University of Texas and University of Illinois report that changes in the sun's magnetic activity may produce changes in cosmic rays striking the Earth. These cosmic rays in turn change the distribution of charged particles in the in clouds (electrical currents) which affect how many ice crystals are formed. This can impact the formation and life cycle of clouds.

Though sunspot activity has been declining since 1960, research concerning the sun's impact on Earth's climate may reveal some additional information about feedback mechanisms which are related to global warming or El Nino.

Twin Cities Almanac for March 27th:

The average MSP high temperature for this date is 44 degrees F (plus or minus 11 degrees standard deviation), while the average low is 26 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for March 27th:

MSP weather records for this date include: highest daily maximum temperature of 75 degrees F in 1946; lowest daily maximum temperature of 24 degrees F in 1899; lowest daily minimum temperature of 5 degrees F in 1921; highest daily minimum temperature of 57 degrees F in 1910; record precipitation of 1.24 inches in 1961; and record snowfall of 5.6 inches in 1965. There have been 14 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 17 inches in 1965. The worst windchill conditions on this date were -35 to -40 degree F values which occurred in 1921.

Average dew point for March 27th is 27 degrees F, with a maximum of 58 degrees F and a minimum of 0 degrees F.

All-time state records for March 27th:

Scanning the state climatic data base: the all-time high for this date is 85 degrees F at Thief River Falls (Pennington County) in 1946; the all-time low is -29 degrees F at Red Lake Falls (Red Lake County) in 1955.

Word of the Week: Ice Spar

This term is used to refer to a stout beam, raft or spear-like protrusion of ice extending out from a glacier or an iceberg. Spars may be entirely visible or partially submerged in water. Such a feature is suspected to have been the cause of rupture in the sides of the ocean liner Titanic, as the vessel avoided a head-on collision with an iceberg, but skirted along one side of it.

Outlook:

Warming trend is likely to keep temperatures above normal for the balance of March. But, moisture advection across the state is significant, with dew points in the 40s and 50s. Chance of showers and thunderstorms Sunday and Monday as a low pressure system moves out of the central plains and over the Great Lakes. Windy conditions will prevail during this period. There may be a respite from the wind and rain for Tuesday and Wednesday, then another low pressure system will bring rain and wind for Thursday. Daytime high temperatures will be mostly in the 50s and 60s, with lows in the 30s and 40s. To: Perry Finelli, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, March 27, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: Did the weather have anything to do with the sinking of the Titanic?

Topic: Dave Barry's Analysis of El Nino

Topic: The Sun's Impact on the Climate of Earth

file:///G|/1998/WeatherTalk_1998-03-27.txt[9/22/2015 3:52:05 PM] form the ozone molecule. More uv radiation is absorbed by this ozone and the heat is translated to the lower atmosphere by natural circulation patterns. Lastly, other scientists from the University of Texas and University of Illinois report that changes in the sun's magnetic activity may produce changes in cosmic rays striking the Earth. These cosmic rays in turn change the distribution of charged particles in the in clouds (electrical currents) which affect how many ice crystals are formed. This can impact the formation and life cycle of clouds.

Twin Cities Almanac for March 27th:

The average MSP high temperature for this date is 44 degrees F (plus or minus 11 degrees standard deviation), while the average low is 26 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for March 27th:

Average dew point for March 27th is 27 degrees F, with a maximum of 58 degrees F and a minimum of 0 degrees F.

All-time state records for March 27th:

Word of the Week: Ice Spar

file:///G|/1998/WeatherTalk_1998-03-27.txt[9/22/2015 3:52:05 PM] Outlook:

file:///G|/1998/WeatherTalk_1998-03-27.txt[9/22/2015 3:52:05 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, April 3, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: March Climate Summary for Minnesota

After significant daily temperature departures, both above and below normal, most Minnesota communities reported a mean March temperature which only deviated by 1 or 2 degrees from the long term average. Parts of western and southwestern Minnesota reported below normal mean March temperature, ending a string of above normal monthly temperatures which started in December. Very cold temperatures during the second week of the month may have caused significant damage to certain plants in the landscape, including alfalfa, but a complete assessment of the situation has not yet been done.

Precipitation during March was well above normal for many places. MSP reported 4.56 inches for the month, the second highest total for March in the climate record, topped only by 4.75 inches in 1965. Sioux Falls, SD reported 4.08 inches of precipitation for March, the most for the month since 1948. The only parts of Minnesota reporting less than normal precipitation were generally in the far north central and northwestern counties.

Topic: New Director of the National Weather Service

Brigadier General John J. Kelly, former head of the Air Force Air Weather Service (AWS) was appointed as the 13th Director of the National Weather Service in mid February. MPR listenrs might recall that General Kelly headed a federally appointed committee to review the operations of the National Weather Service last year, following the departure of former head Dr. Elbert (Joe) Friday. One of the findings of his review committee was the conclusion that federal budget cuts to the agency were too severe and might threaten public safety with the loss or degradation of critical weather services. His review prompted a restoration of some of the previous budget cuts to the National Weather Service.

Though many directors of the National Weather Service have come from research or academic backgrounds, General Kelly is not the first to come from the military. Francis Reichelderfer, was a navy commander when he was appointed as director of the National Weather Service in 1938 under the FDR administration. He served in that capacity for over 25 years. General Kelly's background in the Air Weather Service (AWS) is viewed as a positive attribute. The history of the Air Weather Service is a storied one: On March 25, 1948, Major Ernest Fawbush and Captain Robert Miller of the AWS at Tinker Air Force Base in Oklahoma issued the first ever tornado warning, three hours ahead of the storm's arrival; in the spring of 1944, the AWS conducted the first hurricane reconnaisance flight using a specially instrumented B-25 bomber; during the Berlin Airlift of 1948-1949 the weather forecasts for 189,000 mostly humanitarian flights into and out of the blockaded Berlin were provided by AWS forecasters; AWS forecasters provided weather information for Operation Desert Storm in Iraq; and AWS continues to this day to supply the weather support for NASA's space shuttle missions.

Topic: Weather and Your Aches and Pains

A review article by Dr. Donald Quick, director of clinical research at the Minneapolis Sports Medicine Center, appears in the March issue of Minnesota Medicine. Dr. Quick reviews 16 published studies of weather and joint pain in patients suffering from a range of conditions, including rheumatoid arthritis, osteoarthritis, and fibromyalgia.

He finds a number of flaws in these studies, which make it difficult to interpret their results. One pervasive error he notes is the failure to keep subjects uninformed about weather reports. Information about weather conditions can unconsciously influence patients to report pain. Many studies show relationships between pain and humidity, atmospheric pressure, temperature, and wind, but Dr. Quick feels that these variables are not particularly well quantified. He concludes that the relationship of pain to weather is a difficult hypothesis to prove, even though from the patient point of view, the effect is quite real. He offers the opinion that weather-related joint pain is more psychological than physiological.

Topic: Tornado Damages in Southern Minnesota

This past Sunday, March 29 will go down in the weather history book. During a period of more than 5 hours, beginning about 2:30 pm the National Weather Service issued 22 severe thunderstorm warnings and 12 tornado warnings across southern Minnesota. Damage surveys show that seven separate tornadoes were spawned from a large supercell thunderstorm which tracked from Nobles County NE through Rice and Dakota Counties. There were also numerous reports of hail.

Using the Fujita Scale, which is based on the types of damages left in the path of a tornado, National Weather Service personnel have determined that two F-3 tornadoes (wind speeds from 158- 206 mph) caused the severe damages in Comfrey (Brown County) and St Peter (Nicollet County). The other five tornadoes were of lesser intensity.

Records show only six cases of documented March tornadoes in Minnesota, but the ones on Sunday were by far the strongest and most destructive. In fact, the total economic consequences (insurance claims, FEMA disaster relief, state aide, and infrastructure recovery and repair) will likely exceed any previous record amounts in the state from tornadic activity.

Like the flood disaster of 1997, the victims of this disaster must face the psychological consequences and challenges of materially losing so much, but rebuilding their homes and their community with perhaps a renewed vision.

Twin Cities Almanac for April 3rd:

The average MSP high temperature for this date is 48 degrees F (plus or minus 11 degrees standard deviation), while the average low is 30 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for April 3rd:

MSP weather records for this date include: highest daily maximum temperature of 80 degrees F in 1921; lowest daily maximum temperature of 27 degrees F in 1954; lowest daily minimum temperature of 9 degrees F in 1954; highest daily minimum temperature of 52 degrees F in 1921; record precipitation of 0.84 inches in 1974; and record snowfall of 5.9 inches in 1974. There have been just 4 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 9 inches in 1975. The worst windchill conditions on this date were -20 to -25 degree F values which occurred in 1982 and 1995.

Average dew point for April 3rd is 26 degrees F, with a maximum of 58 degrees F and a minimum of -5 degrees F.

All-time state records for April 3rd:

Scanning the state climatic data base: the all-time high for this date is 86 degrees F at Beardsley (Big Stone County) in 1929; the all-time low is -19 degrees F at Big Falls (Koochiching County) in 1954 and at Thorhult (Beltrami County) in 1975.

Words of the Week: Pluviometric coefficient

Taken from the Latin root words pluvio meaning rain and metre meaning to measure, this term refers to a manner of expressing rainfall as a ratio of the average monthly value to one-twelfth of the normal annual amount. Sometimes called an isomer, it is a way for climatologists to express each months "share" of the annual precipitation for a particular location. Values less than one, represent less than an equal share of the annual precipitation (a relatively dry month), while values greater than one represent a greater than equal share of the annual precipitation. Taking MSP average monthly precipitation values as an example shows that February's .88 inch average represents less than a 0.4 share (pluviometric coefficient), while June's 4.05 inch value represents a 1.7 share (pluviometric coefficient). This variability in the pluviometric coefficient is typical of mid latitude continental climates, while equatorial and marine type climates often have values that are uniformly close to one.

Outlook:

Somewhat quiet weather over the coming weekend, with temperatures a few degrees warmer than normal. A low pressure system will bring a chance for precipitation starting on Monday, particularly up north. There will be another chance for precipitation Wednesday through Friday of next week as a low pressure center comes out of the central plains. Winds will increase and temperatures will remain warmer than normal, but glimpses of the sun will be rare.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, April 10, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: In doing a science fair project this winter, I found a July total rainfall of nearly 18 inches at the MSP airport in 1987. Is this a record monthly total for Minnesota?

Answer: No. Amid all of the record setting weather events of 1997, a rather significant rainfall record was set in Minnesota, and yet has remained unreported. A volunteer rainfall observer in Goodhue County, in the rolling landscape just south of Red Wing reported a July rainfall total of 20.4 inches. Sixteen days with measurable rainfall were reported, including four days with rainfall in excess of 2.5 inches. This total exceeds any previous monthly total rainfall observed in the state, and is the first time that over 20 inches has been recorded in one month.

Topic: Early Outlook for the 1998 Atlantic Hurricane Season

Dr William Gray and colleagues at Colorado State University have revised their earlier predictions for the coming Atlantic hurricane season, which starts on June 1st. Their analysis is based on such features as upper air wind patterns, rainfall over West Africa and the dissipation of the current El Nino episode.

They predict 10 named storms for the 1998 Atlantic hurricane season (storms with sustained winds of at least 39 mph), 6 hurricanes (about average in the Atlantic), and 2 intense hurricanes (category 3, 4, or 5). The 1997 Atlantic hurricane season produced 7 named storms, so their forecast is for a more active season, but not as active as 1995 and 1996.

For teachers or others with an interest in hurricane information, this forecast and other details about recent hurricane seasons can be found at the following web sites..... http://cirrus.sprl.umich.edu/wxnet/tropical.html http://typhoon.atmos.colostate.edu/forecasts/

Topic: New Satellite to Monitor the Sun

Data from NASA's Advanced Composition Explorer satellite are now processed daily by NOAA forecasters. The sensors on this satellite, pointed towards the sun, monitor solar winds and geomagnetic activity. This allows scientists to predict geomagnetic storms that release masses of highly energetic charged particles which strike the Earth's magnetic field and sometimes disrupt communications and electronic systems. NOAA staff will now be able to alert satellite, communications, and electronic systems operations administrators about potentially disruptive geomagnetic storms and give them sufficient lead time to adjust their operations to minimize disruptions.

Topic: Lake Ice-Out Dates for 1998

The DNR-State Climatology Office is monitoring lake ice-out around the state. Many lakes in southern Minnesota are already ice-free. The climatologists for the DNR predict that many other lakes will record ice-out from 5 to 10 days earlier than normal this year thanks to the mild winter.

Those interested in monitoring the loss of lake ice around the state or seeing the prediction for a particular location, can browse the Climatology Working Group web site at.... http://www.soils.agri.umn.edu/research/climatology/doc/ice_out_98.html

Twin Cities Almanac for April 10th:

The average MSP high temperature for this date is 53 degrees F (plus or minus 11 degrees standard deviation), while the average low is 33 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for April 10th:

MSP weather records for this date include: highest daily maximum temperature of 88 degrees F in 1977; lowest daily maximum temperature of 33 degrees F in 1997; lowest daily minimum temperature of 18 degrees F in 1962; highest daily minimum temperature of 55 degrees F in 1977; record precipitation of 0.69 inches in 1891; and record snowfall of 6.0 inches in 1891. There have been just 3 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 6 inches in 1980.

Average dew point for April 10th is 29 degrees F, with a maximum of 58 degrees F and a minimum of 3 degrees F.

All-time state records for April 10th:

Scanning the state climatic data base: the all-time high for this date is 92 degrees F at Madison (Lac Qui Parle County) and Browns Valley (Traverse County) in 1977; the all-time low is -8 degrees F at Brimson (St Louis County) and Gunflint Lake (Cook County) in 1989.

Words of the Week: lamb storm, lamb-showers, or lamb-blasts

Our April snow showers, not uncommon to northern Minnesota, do not have a colloquial name associated with them. But, they certainly do in England and Scotland. These terms are used to refer to nuisance storms which produce a light falling of snow in the spring when new lambs are born, most often during March or early April. More severe snow storms or squalls during lambing can be lethal to the newborn lambs, so the U.K. Meteorological Office provides special forecasts to sheep producers during the spring season to help them avoid or at least anticipate any weather-related difficulties.

Outlook:

Sunny and warm on Saturday with temperatures well above normal. Increasing cloudiness late Saturday with a chance for storms in western Minnesota. Chance of thunderstorms Sunday and Monday, remaining somewhat unsettled but cooler on Tuesday. Another chance for showers and thunderstorms late Wednesday through Thursday, especially in the south. Breezy most days, but temperatures will remain warmer than normal throughout the period. Comments to MPR for April 17, 1998

Topic: How fast does spring move northward?

This question seems to come up just about every year. Several climatologists have studied this question with different measures or indices of spring. Three separate measures of the migration of spring which have been used in Minnesota are described below:

1) Historically the dates of "ice-out" on Minnesota lakes (the date that lakes are free of any ice cover) range from early April in southern counties to early May in the far northeast. Taking the distance from south to north and dividing by the number of days equates to a migration in ice-out dates of roughly 15 miles per day.

2) The 45 degree F isotherm for average air temperature is sometimes used as a marker of spring, since much of the native vegetation begins to grow and respond phenologically at this temperature. Using climatological maps of the Great Lakes Region which show the average first date of the 45 degree F mean temperature isotherm, spring is seen to migrate at the rate of 22 miles per day.

3) The apparent movement of the sun to higher elevation angles in the sky is another, more astronomical marker of spring. Examining the period from the vernal equinox on March 20 (when the sun is 90 degrees over the equator) to the summer solstice on June 21 (when the sun is over the Tropic of Cancer, at 23.5 degrees north latitude) shows that the overhead sun migrates a total of 23.5 degrees latitude, or 1567 miles. Dividing the total miles by the number of days equates to an average migration rate of 17 miles per day.

At least all three measures of spring migration, though somewhat different, seem to estimate values that are similar.

Topic: 1998 Agricultural Season Getting Underway

Agricultural soils have thawed and drained in may places and farmers are starting to work coarse textured soils. In fact it is estimated that some small grains have already been planted. Soils temperatures at the 4 inch depth are averaging in the 40 to 45 degrees F range up north, and near 50 degrees F or more in southern counties. Planting will begin in earnest around the state the week of April 20th. Timely planting is so critical for many producers that they will often work 16 to 20 hour days to take full advantage of good spells of weather. This in part explains why you see so many headlights moving along farm fields at night during the spring.

file:///G|/1998/WeatherTalk_1998-04-17.txt[9/22/2015 3:52:05 PM] Twin Cities Almanac for April 17th:

The average MSP high temperature for this date is 58 degrees F (plus or minus 12 degrees standard deviation), while the average low is 38 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for April 17th:

MSP weather records for this date include: highest daily maximum temperature of 85 degrees F in 1985; lowest daily maximum temperature of 33 degrees F in 1953; lowest daily minimum temperature of 19 degrees F in 1953; highest daily minimum temperature of 61 degrees F in 1976; record precipitation of 1.44 inches in 1975; and record snowfall of 2.7 inches in 1939. There have been just 2 measurable snowfalls in the Twin Cities on this date since 1948. The greatest snow depth on this date was 5 inches in both 1961 and 1983.

Average dew point for April 17th is 32 degrees F, with a maximum of 62 degrees F and a minimum of 32 degrees F.

All-time state records for April 17th:

Scanning the state climatic data base: the all-time high for this date is 91 degrees F at Tracy (Lyon County) in 1914; the all-time low is -5 degrees F at Gunflint Lake (Cook County) in 1983.

Words of the Week: talik or tabetisol

These are Russian words, both used to refer to a layer of permanently unfrozen ground within regions of permafrost. Usually refers to a layer that lies above the permafrost, but these terms may also relate to layers of soil within or beneath the permafrost. Talik or tabetisol layers may vary from a few inches to several feet in thickness and support a number of micro- organisms which are tolerant to cold temperatures. These soils are usually found at fairly high latitudes.

Forecast for April 18-24:

High pressure will dominate the region for an extended period beginning this weekend. Sunny skies, lighter winds, and near normal temperatures should persist for most of next week. This will allow rapid progress in spring planting around the state.

file:///G|/1998/WeatherTalk_1998-04-17.txt[9/22/2015 3:52:05 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, April 24, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: Are minimum temperatures ever below zero degrees F in Minnesota during April, and if so, what is the latest date?

Answer: Yes, in northern Minnesota counties there have been several below zero minimum temperatures recorded during April. They usually occur when winter snow cover persists well into the month. The latest below zero minimum temperature I could find in the climate record was -3 degrees F which occurred at Tower, MN on April 19, 1897. The coldest April minimum I could find also occurred at Tower, MN on April 6, 1982 when the temperature plunged to -22 degrees F.

Topic: Crop Insurance

With warming soil temperatures, sunny skies and light winds farmers are planting crops at a rapid pace this week around the state. Some crop producers use various crop insurance policies to cover themselves against yield and income losses due to bad weather, plant diseases, or insect damage. The evolution of insurance products for the crop producers in recent years has mandated better record keeping. For many insurance policies, farmers can benefit from having kept yield and production costs for four or more years. This Actual Production History (APH) provides average yield figures for major crops which may be used as a basis for insurance coverage. This is often better than accepting insurance coverage for default yield values which have been established for various regions by the USDA National Agricultural Statistics Service.

Multiple Peril Crop Insurance (MPCI) covers losses due to drought, floods, excessive moisture, hail, wind, and frost or freeze damage. Such policies also insure against some losses from insects and diseases. In our region, the vast majority of claims are associated with drought (1988), excess moisture (1991, 1993, 1997), or hail. In Minnesota these features of the weather often account for over 75 percent of the insured coverages paid out in any given year.

Crop insurance serves as one of the risk management tools used by Minnesota crop producers. Early planting is another advantage in the risk management game, since yields tend to be better and harvests are generally less subject to poor weather conditions. This may prove to be an asset to Minnesota farmers this spring, as they continue to make rapid progress in planting well before May 1st.

Twin Cities Almanac for April 24th:

The average MSP high temperature for this date is 60 degrees F (plus or minus 11 degrees standard deviation), while the average low is 41 degrees F (plus or minus 9 degrees standard deviation).

MSP Local Records for April 24th:

MSP weather records for this date include: highest daily maximum temperature of 84 degrees F in 1962; lowest daily maximum temperature of 41 degrees F in 1944; lowest daily minimum temperature of 26 degrees F in 1956; highest daily minimum temperature of 62 degrees F in 1915; record precipitation of 1.43 inches in 1908; and record snowfall of 0.3 inches in 1902. It has not snowed on this date since at least the end of World War II.

Average dew point for April 24th is 35 degrees F, with a maximum of 66 degrees F and a minimum of 12 degrees F.

All-time state records for April 24th:

Scanning the state climatic data base: the all-time high for this date is 92 degrees F at Madison (Lac Qui Parle County) in 1962; the all-time low is 9 degrees F at Baudette (Lake of the Woods County) in 1909.

Words of the Week: The Intertropical Convergence Zone (ITCZ)

Highly visible on satellite imagery of the Earth's equatorial regions, this is the somewhat narrow discontinuous belt along either side of the equator where convective clouds and thunderstorms often dominate. The easterly trade winds (NE in the northern hemisphere and SE in the southern hemisphere) converge here, forcing air to rise which triggers convective storms and squalls. The storminess is often more prevalent over the oceans than over the equatorial land surfaces.

Outlook:

A fairly strong low pressure system will cross over the state over the weekend, bringing showers, thunderstorms and relatively strong winds. Temperatures will remain above normal, but some of the showers will be around through Monday. Somewhat drier on Tuesday and Wednesday, then a chance for more showers later next week. Temperatures will continue to average above normal. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, May 1, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: When was the last time the Twin Cities saw snowfall in May?

Answer: The last measurable snowfall in May was in 1991 on the 5th when 0.3 inches was recorded at the airport. The last snowfall on May 1st (today's date) was 0.3 inches in 1967. Climatologically, using the past 100 years of data, the Twin Cities has a 10 to 15 percent chance of seeing measurable snowfall in May. The heaviest snowfalls in May occurred in 1892 and 1935 when 3.0 inches of snow occurred in the Twin Cities. The storm on May 1-2 of 1935 produced the most ever snowfall in Minnesota for the month, including 11 inches at Wheaton, 8 inches at Fergus Falls and Beardsley, 5 inches at Campbell and Wadena, 4 inches at Collegeville and Maple Plain. This storm was accompanied by strong winds and plummeting temperatures which produced windchill values near zero. Over 1 inch of ice built up on power lines and brought down over 500 poles.

Topic: Preliminary April Climate Summary

April has been drier than normal for most of Minnesota, except for a few communities in west central, south-central and southeastern counties which received heavier showers from small thunderstorm systems. The absence of significant precipitation in north-central and northeastern counties has aggrevated the fire danger there, but elsewhere throughout the agricultural landscape, crop producers have benefitted by getting early planting done at a much accelerated pace. Temperatures for April have averaged out to be 2 to 5 degrees F warmer than the 30 year average, continuing the warm trend which was observed this winter. Some observations of daytime relative humidities ranging from only 15 to 25 percent were unusually low for April and a reminder of what it was like in 1987 and 1980.

Topic: Gentle Reminder About the UVI

The sunny and pleasant weather of late has brought out early sunbathers. But, don't underestimate the effects of the spring sun. The National Weather Service Forecast Office issues a forecast of the next day Ultra Violet Index (UVI) each afternoon. This product is intended to help people anticipate the level of exposure to the sun and whether or not to protect themselves. The UVI is estimated based on expected intensities at solar noon and ranges from 0-15. The exposure categories used are: minimal (0-2), low (3-4), moderate (5-6), high (7-9) and very high (10 and above).

This is a cooperative effort between the National Weather Service and the Environmental Protection Agency/Center for Disease Control, whose slogan is be "sun wise." Recent sunny days have produced a UVI of category 5, moderate exposure, which suggests that those people with particularly sensitive eyes and skin should be wearing some form of protection if they are out in the sun for long periods.

Topic: Arbor Day and the Value of Trees

I failed to mention an appreciation for Arbor Day last week, but I was reminded recently by Kirk Brown of the Tree Trust about the many beneficial aspects of trees in the landscape.

Trees consume large quantities of carbon dioxide and respire oxygen; in the rural landscape, trees in shelterbelts provide wildlife habitat, wind protection, and reduce soil erosion; along roadsides trees serve as living snow fences, trapping snow and helping to keep roads open and safe during the winter; in residential areas trees provide shade and greatly moderate the extremes of wind and temperature, reducing energy used for heating and air conditioning; trees help filter out dusts and odours and buffer noise pollution; and most recently researchers report that trees in the urban landscape seem to have a positive emotional effect on people, presenting more attractive scenery, and a calming, stress reducing type of response.

Twin Cities Almanac for May 1st:

The average MSP high temperature for this date is 63 degrees F (plus or minus 13 degrees standard deviation), while the average low is 43 degrees F (plus or minus 9 degrees standard deviation).

MSP Local Records for May 1st:

MSP weather records for this date include: highest daily maximum temperature of 91 degrees F in 1959; lowest daily maximum temperature of 33 degrees F in 1909; lowest daily minimum temperature of 24 degrees F in 1909; highest daily minimum temperature of 64 degrees F in 1934; record precipitation of 1.26 inches in 1983; and record snowfall of 3.0 inches in 1935. It last snowed on this date in 1967 (0.3 inches)

Average dew point for May 1st is 36 degrees F, with a maximum of 64 degrees F and a minimum of 8 degrees F.

All-time state records for May 1st:

Scanning the state climatic data base: the all-time high for this date is 100 degrees F at Beardsley (Big Stone County) in 1959; the all-time low is 4 degrees F at Pine River Dam (Crow Wing County) in 1909, when they reported 11 inches of snow on the ground.

Words of the Week: Ventifact and Dreikanter

These terms are used both in geology and climatology. Ventifact is taken from the Latin root words, ventus for wind, and factum meaning "to make." Like artifact (human-made), ventifact is the term used to refer to a stone or rock which has been sculptured by wind blown sediments. Its surface may appear worn, polished or multifaceted as a result of a sort of long term sandblasting effect. These types of stones or rocks are found in dry arctic climates, near glaciers, or in desert regions.

The dreikanter, a German term, refers to a three edged or three faceted type of ventifact. Exposed to wind blown sediments coming from different directions, the carving and sculpturing of the surface may give distinctly different appearances to the sides and edges of the stones.

Outlook:

Somewhat unusual situation for Minnesota in the spring as the active area of precipitation remains well south. Chances for precipitation over the weekend and by Tuesday and Wednesday of next week, but not much water vapor to precipitate out from a relatively dry air mass. Cooler temperatures on Sunday and Monday, but warming to above normal values for most of next week, with many 70s around the state. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, May 8, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: How long does a water molecule stay in the Earth's atmosphere?

This is an interesting question. Hydrologists have studied this based on evaporation rates, condensation rates and cloud forming processes such as lifting air over mountains. The average residence time of a water molecule within a cloud in the form of a droplet or ice crystal is estimated to be 1-3 hours; traveling throughout the atmosphere in air currents as a water vapor molecule, it is estimated to have an average resident time of 9-10 days. Stored in the top soil, a water molecule might remain for two weeks, before being taken up through a plant root system. Or it may take up to 3 months before percolating to shallow acquifers below the plant rooting zone. Once in a ground water acquifer, a water molecule may remain for 10,000 years or longer. This is true for water stored in the polar ice caps or in major glaciers around the world as well.

Topic: Moisture Needed by Crops

Though an earlier than normal planting season has raised hopes for good crops this year, many places in the state could use a good rain. Subsoil moisture remains very good in most areas, but very low humidities, warm temperatures and sunny days have really dried out the soil surface layer. This is apparent in driving through the countryside and seeing the clouds of dust being raised by tractors and implements going across fields. Even small amounts of rainfall will help seeds establish initial roots to tap the deeper soil moisture. Some crop producers with irrigation systems have already started watering to insure germination and a good, even emerging crop stand. Many alfalfa fields will be ready to cut soon, but additional rain would really improve the yield prospects for the first cutting.

Topic: The 1998 Atlantic Hurricane Season Begins

For science teachers and students, or those who like to follow tropical weather developments, the Atlantic hurricane season officially begins on May 15th. Daily forecasts and discussions, along with satellite imagery will be available at the National Hurricane Center web site on the Internet: http://www.nhc.noaa.gov

The four most costly hurricanes have occurred since 1989 (Andrew in 1992, Hugo in 1989, Fran in 1996, and Opal in 1995) totaling nearly $40 billion in losses and damages. Last year was relatively quiet with 7 named tropical storms and only 3 hurricanes. But, this year is expected to be about normal, with a forecast for 10 named tropical storms and perhaps 6 hurricanes. The first storm of the season will have the name Alex.

Twin Cities Almanac for May 8th:

The average MSP high temperature for this date is 65 degrees F (plus or minus 11 degrees standard deviation), while the average low is 45 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for May 8th:

MSP weather records for this date include: highest daily maximum temperature of 87 degrees F in 1896; lowest daily maximum temperature of 41 degrees F in 1924; lowest daily minimum temperature of 28 degrees F in 1960; highest daily minimum temperature of 67 degrees F in 1896; record precipitation of 1.21 inches in 1938; and record snowfall of 0.5 inches in 1923.

Average dew point for May 8th is 38 degrees F, with a maximum of 67 degrees F and a minimum of 6 degrees F.

All-time state records for May 8th:

Scanning the state climatic data base: the all-time high for this date is 102 degrees F at Beardsley (Big Stone County) in 1934; the all-time low is 10 degrees F at Pine River Dam (Crow Wing County) in 1907.

Word of the Week: Trowel

Not the kind used to smooth out new cement. This term is used by some meteorologists (Canadian) to refer to a tongue or wedge of warm air isolated aloft. This sometimes happens when a cold front overtakes a warm front (forming an occluded front), lifting the warmer air away from the surface. It is usually relatively short- lived, but shows up as an unusual layer of warm air on an upper air sounding. Trowels sometimes signal the possibility of freezing rain or an ice storm, as the warm moist air aloft reaches saturation and precipitates through a colder layer of air below, causing the droplets to become supercooled and freeze on impact with the Earth's surface. My recollection is that a trowel of warm air aloft contributed to the terrible ice storm over northern New England and the St Lawrence River Valley in Canada last January that caused widespread power outages.

Outlook:

Temperatures should be a few degrees either side of normal over the next week, with plenty of sunshine. Should be favorable outdoor conditions this weekend for both the fishing opener and Mother's Day on Sunday. A chance of rainfall in southeastern Minnesota later on Sunday and Monday, otherwise mostly dry around the state until late Wednesday, when a larger low pressure system may bring a chance for showers statewide lasting into Thursday and Friday. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, May 15, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: How often does it hail in Minnesota and when are the peak frequencies of hail?

Answer: The Crop-Hail Insurance Industry has kept statistics on this feature of the weather. The average annual number of days when hail is reported varies around the state, from under 2 days per year in the far north, to just over 4 days per year in the extreme southwestern counties. The peak frequency of hail is in the months of May and June, with April not too far behind. In fact those three months account for nearly 60 percent of the historical hail reports in the state. The most common time of day when hail is reported ranges from the late afternoon to early evening.

Topic: New Monthly and Seasonal Outlooks

The Climate Prediction Center released the new monthly and seasonal climate outlooks on Thursday of this week (May 14th). For the western Great Lakes states, including Minnesota and Wisconsin, the June outlook favors below normal temperatures (quite contrary to the recent trend) and above normal precipitation. I am sure the precipitation outlook will be viewed favorably by those at the Fire Weather Center in Grand Rapids, MN who have been so concerned about forest fires in north-central and northeastern Minnesota, and by some agricultural producers who would like to see more rainfall for the early planted crops.

The seasonal outlook for June through August favors above normal precipitation for the entire upper midwest, including Minnesota, while the temperature outlook does not favor significant departures from normal climatology.

Topic: Climate Extremes

During one of my recent classes at the university, I found it interesting to compare climate extremes for the United States, and those for the state of Minnesota.

NOAA accepted climate extremes for the United States:

Temperature (F) Maximum 134 Jul 10, 1913 Greenland Ranch, CA Minimum -80 Jan 23, 1971 Prospect Creek, AK Max 24 hr Temp Change 100 Jan 23-24, 1916 Browning, MT

Snow (in.) Maximum 24 hr 75.8 Apr 14-15, 1921 Silver Lake, CO Seasonal (Jul-Jun) 1122 1971-1972 Paradise RS, WA Max Snow Depth 451 Mar 11, 1911 Tamarack, CA Rain (in.) Maximum 24 hr 43 July 25-26, 1979 Alvin, TX Least Annual 0.00 1929 Death Valley, CA Maximum Annual 704.83 1982 Kukui, HI Dry period 767 days 10/3/12-11/8/14 Bagdad, CA

Wind (mph) Maximum gust 231 Apr 12, 1934 Mt Washington, NH

Pressure (in.) Lowest 26.35 Sep 2, 1935 (hurricane) Matecumbe Key, FL Highest 31.85 Jan 31, 1989 Northway, AK

Analogous climate extremes for Minnesota:

Temperature Maximum 114 Jul 29, 1917 Beardsley Jul 6, 1936 Moorhead Minimum -60 Feb 2, 1996 Tower Max 24 hr Temp Change 71 Apr 3, 1982 Lamberton

Snow (in.) Maximum 24 hr 29.0 Nov 1, 1991 Cook (maximum from single storm 36.9, 10/31-11/3/91, Duluth) Seasonal (Jul-Jun) 153.9 1995-1996 Lutsen Max Snow Depth 88 Feb 15-21, 1969 Meadowlands

Rain (in.) Maximum 24 hr 10.84 Jul 22, 1972 Fort Ripley (maximum from single storm 36, July 17-19, 1867 Sauk Centre) Least Annual 6.37 1976 Ortonville Maximum Annual 53.52 1991 St Francis Dry period 79 days 11/9/43-1/26/44 Beardsley, Canby, Marshall, Dawson

Wind (mph) Maximum gust 110 Aug 20, 1904 (tornado) St Paul

Pressure (in.) Lowest 28.40 Jan 11, 1975 Grand Portage Highest 31.11 Jan 21, 1922 Collegeville

Twin Cities Almanac for May 15th:

The average MSP high temperature for this date is 68 degrees F (plus or minus 11 degrees standard deviation), while the average low is 47 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for May 15th:

MSP weather records for this date include: highest daily maximum temperature of 91 degrees F in 1931; lowest daily maximum temperature of 39 degrees F in 1907; lowest daily minimum temperature of 31 degrees F in 1907; highest daily minimum temperature of 65 degrees F in 1894; record precipitation of 1.95 inches in 1911; and record snowfall of 0.8 inches in 1907. Average dew point for May 15th is 42 degrees F, with a maximum of 69 degrees F and a minimum of 21 degrees F.

All-time state records for May 15th:

Scanning the state climatic data base: the all-time high for this date is 96 degrees F at Beardsley, Canby, and Fergus Falls in 1931; the all-time low is 18 degrees F at Cotton (St Louis County) in 1967.

Word of the Week: CAPE

During the thunderstorm season in Minnesota, you may occasionally hear meteorologists use the term CAPE values. What does that mean? CAPE is an acronym, as is often the case with the National Weather Service. It stands for Convectively Available Potential Energy, an index derived from 12 hourly radiosonde data (balloons), to assess the potential for convective thunderstorms.

As warm air rises it may cool and reach the saturation point where condensation occurs. This process releases energy to the atmosphere (at the rate of 585 calories per gram of water). CAPE values are used to rate the potential energy from condensation between the 850 mb level and the 300 mb level in the atmosphere (roughly 5000 to 30,000 ft above the Earth). These integrated values are expressed in joules/kg. CAPE values in the range from 600 to 2000 are somewhat average. Values less than 600 indicate a very stable atmosphere, while values over 2000 indicate enough energy to produce convective thunderstorms. Values in excess of 2500 show enough energy to produce strong thunderstorms and may be used as a justification for the National Severe Storms Forecast Center (NSSFC) in Norman, OK to issue a severe thunderstorm watch.

Daily forecasts by the NSSFC can be accessed on the Internet at: http://www.nssl.uoknor.edu/~spc/products/index.html

Outlook:

With increasing dewpoints and southerly winds, there will likely be some convective shower activity and thunderstorms around the state early this weekend, with a possible respite on Sunday. Increasing chances for rainfall again Monday and continuing through much of next week. Temperatures will remain several degrees warmer than average for mid-May.

To: Perry Finelli, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, May 22, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: People always say that "normal" weather hardly ever occurs in Minnesota. How often do we record normal temperatures on a given date?

Answer: This question has been raised a number of times and the simple answer is that regardless of the time of year, "normal" temperatures occur pretty infrequently. A case in point is to take the normal high and low temperatures for MSP on today's date (May 22). The normal or long term average high temperature is 72 degrees F and the normal low is 51 degrees F. Examining the records since 1891 (107 years) shows that 72 degrees F has been recorded as the daily maximum only 8 times, while 51 degrees F as the daily minimum has been recorded only 3 times. If we allow some variation around normal, say plus or minus 3 degrees F, the frequency of occurrence improves to 30 to 35 percent of all years.

MPR listener question: I have heard you say that for Minnesota, May is the month when the average difference between the daily minimum and maximum temperature is greatest. Why? Has there ever been a day in May when the daily temperature range was only 1 or 2 degrees F?

Answer: The relatively larger difference between the minimum and maximum temperature during May is due to a combination of factors: One is the increasing daylength and sun angle, allowing for longer and more intense heating of the landscape, particularly under relatively sunny skies; secondly, there are still large temperature differences between air masses that cross over the state, and therefore large temperature changes can accompany frontal passages and wind shifts. There are probably other reasons as well, but I think these are the major ones.

The answer to your second question is no, there has never been a date in May when the temperature varied only 1 or 2 degrees F in the Twin Cities area. Such conditions are far more prevalent during the season of long nights and small sun angles. For example, the only four occasions in the MSP record when the difference between the daily maximum and minimum was just 1 degree F have all occurred in December. Indeed, the majority of dates when the daily temperature change has only been a few degrees F have occurred in the months of November and December, a period that is dominated by long nights and very cloudy skies, with low ceilings.

Topic: The divine wind of Japan

During the second half of the 13th century, the mongol emperor Kublai Khan, grandson of Genghis Khan, ruled China. He also wished to conquer Japan and twice sent his warriors and ships to do so. In the fall of 1274, during a siege of Kyushu, he lost an estimated 13,000 warriors and hundreds of ships when they ignored a wind shift and the onset of a typhoon. Again, in 1281, Kublai Khan sent an even larger force to conquer Kyushu, but in August a large typhoon, lasting two full days struck the island and caused most of the Mongol ships to flounder, and thousands of warriors to drown. This second invasion attempt was described by Marco Polo. After these two tragedies, Kublai Khan executed the invasion commanders, and abandoned his attempts to conquer Japan.

The Japanese people were powerfully impressed by nature's intervention to save them in these two battles. Many thought it was divine intervention and in the subsequent stories about the storms, they were called "kamikaze" or divine wind (kami for god, and kaze meaning wind). This convinced many generations of Japanese that their island nation could not be conquered because the divine wind would always rescue them. During WWII in 1944, their last line of defense became another type of divine wind, the kamikaze pilot who dove his explosive-laden plane into U.S. ships.

In retrospect, Kublai Khan could have used a good meteorologist to tell him not to invade Japan during the typhoon season which can be very active in the western north Pacific Ocean. In fact last year the Typhoon Warning Center on Guam reported a total of 33 named tropical cyclones, 11 of which became super typhoons (sustained winds greater than 150 mph).

Twin Cities Almanac for May 22nd:

The average MSP high temperature for this date is 72 degrees F (plus or minus 10 degrees standard deviation), while the average low is 51 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for May 15th:

MSP weather records for this date include: highest daily maximum temperature of 99 degrees F in 1925; lowest daily maximum temperature of 49 degrees F in 1987; lowest daily minimum temperature of 32 degrees F in 1917; highest daily minimum temperature of 74 degrees F in 1921; record precipitation of 1.20 inches in 1936.

Average dew point for May 22nd is 46 degrees F, with a maximum of 68 degrees F and a minimum of 24 degrees F.

All-time state records for May 22nd:

Scanning the state climatic data base: the all-time high for this date is 100 degrees F at Fairmont, Tracy, and New Ulm in 1925; the all-time low is 21 degrees F at Babbitt (St Louis County) in 1986.

Words of the Week: Belfries, Steeples, Spires, Cupolas, and Barns

These are obviously not meteorological terms! So what do they have in common? In the history of weather recording, these are the most common structures for mounting wind vanes (sometimes called weathervanes). The weathercock, which turns to face the wind and is perhaps the oldest style of wind vane, was first used in bronze form during the 9th century on churches in parts of northern Italy. Subsequently, metallic roosters, doves, eagles and lambs were used for wind vanes on many church and public buildings throughout Europe. In the United States, perhaps the best variety of wind vanes can still be seen across the agricultural landscape mounted on the tops of barns.

Outlook:

Chance of scattered showers and thunderstorms throughout the weekend and early next week, primarily across eastern and southern counties. Temperatures will be a few degrees cooler than normal over the weekend, then warming up to a few degrees warmer than normal next week. Dewpoints will remain in the comfortable range.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, May 29, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Reminder: The National Weather Service Forecast Office in Chanhassen, MN is having an open house, Saturday, May 30th, from 9 am to noon. The public will be treated to tours of the River Forecasting Center, the Weather Service Forecasting Operations Office, and the National Hydrologic Remote Sensing Center, including demonstrations of new technologies (radar, satellite, automated observing systems, and new forecast models).

Topic: Preliminary Climate Summary for May

The above normal temperature trend which began last December carried on through May. Most communities reported average monthly temperatures from 4 to 7 degrees F warmer than normal. Extremes for the month ranged from the upper 20s for several communities in north-central and northeastern Minnesota during the first week in May, to 100 degrees F at Redwood Falls and Olivia on the 18th. May of 1998 will probably rank in the top ten warmest historically, and the warmest since 1988.

Rainfall for the month was mixed. Many northeastern and north- central communities reported rainfall deficits, as well as a number of communities in southwestern Minnesota. Most southern, central and northwestern counties reported rainfall surplus for the month.

Topic: Economic Benefits of Meteorological and Hydrological Services

A World Meteorological Organization publication of a recent International Conference on the Economic and Social Benefits of Meteorological and Hydrological Services highlights some major success stories from governments around the world:

$1000 dollars invested in data collection and a climatological analysis for the design of the Nipawin Dam on the Saskatchewan River in northern Saskatchewan saved Candadian government over $1.5 million in otherwise over-designed spillways.

A microclimatological study, combined with utilization of the National Frost Atlas, saved Israel over $1 million dollars in potential frost damage to new avocado plantations.

Studies in the United Kingdom estimate that weather forecasting for civil and commercial aviation result in savings of over $125 million per year in fuel planning and efficient route selection.

Successful agricultural weather forecasts for late spring frosts in the Minsk region of Belarus in 1994 delayed the planting of vegetables and perhaps saved producers over $1.5 million in reduced yields and/or replanting costs.

MPR listener question: I have heard you talk about maximum daily rainfall in Minnesota being over 10 inches, but what is the maximum rainfall intensity (e.g. rainfall per minute)?

This is a difficult question to answer because we don't have many records of rainfall intensity. According to a 1992 study by the Midwest Climate Center, the maximum 5 minute rainfall accumulation in Minnesota (from historical records) is about 0.75 inches, with a 100 year recurrence interval. The maximum 1 hour rainfall accumulation is about 3 inches (this occurred last July), and is estimated to have a 100 year recurrence interval as well. Similar records published by the Air Force Weather Service show a maximum 5 minute rainfall accumulation of 2.25 inches in Porto Bello, Panama November 29, 1911, and a maximum 1 hour accumulation of 10 inches in Holt, MO on June 22, 1947. I believe that these latter two are accepted world records for 5 minute and 1 hour rainfall intensities.

Twin Cities Almanac for May 29th:

The average MSP high temperature for this date is 74 degrees F (plus or minus 9 degrees standard deviation), while the average low is 54 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for May 29th:

MSP weather records for this date include: highest daily maximum temperature of 91 degrees F in 1934 and 1988; lowest daily maximum temperature of 53 degrees F in 1947; lowest daily minimum temperature of 33 degrees F in 1965; highest daily minimum temperature of 69 degrees F in 1895, 1934, and 1988; record precipitation of 2.49 inches in 1942.

Average dew point for May 29th is 50 degrees F, with a maximum of 72 degrees F and a minimum of 25 degrees F.

All-time state records for May 29th:

Scanning the state climatic data base: the all-time high for this date is 100 degrees F at New Ulm (Brown County) and Tracy (Lyon County) in 1934; the all-time low is 20 degrees F at Bigfork (Itasca County) in 1965.

Words of the Week: Route and Terminal Forecasts

These are both terms used in aviation meteorology. A route forecast is specially derived for the planned flight altitude and path to a destination. One element of this forecast is the route component which is the expected wind aloft parallel to the flight path. It may be positive (tailwind) which assists the aircraft speed and fuel efficiency, or it may be negative (headwind) which diminishes the aircraft speed and fuel efficiency.

A terminal forecast is provided to pilots so that they know what type of weather to expect at their destination air terminal. These forecasts may range from 1 hour ahead to 12 hours ahead, depending on the length of the flight.

Outlook:

Chance of showers and thunderstorms later on Saturday and into Sunday around the state. Temperatures will start to trend a bit cooler, mostly in the 70s. Another chance for showers and thunderstorms Tuesday and Wednesday of next week.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, June 5, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: World Weather Monitoring

Internationally coordinated weather monitoring was created with the birth of the International Meteorological Organization (IMO) in 1878. This was reorganized and renamed by the United Nations in 1947 and has since been called the World Meteorological Organization (WMO), headquartered in Geneva, Switzerland.

Now with over 145 member nations cooperating, routine weather monitoring is performed under the WMO's World Weather Watch program. At standard observation times nearly 4000 land stations, 7000 ships at sea, 1000 radiosondes, and numerous aircraft and satellites transmit environmental data to one of three world meteorological centers: Washington, D.C., Moscow, Russia, or Melbourne, Australia. Maps, charts and forecasts are prepared from these data, then transmitted to dozens of regional meteorological centers around the world.

With the Internet, it is possible to access many of these observational data, charts, and maps. One good source for international observations is the Interactive Weather Information Network maintained by the National Weather Service. The URL is http://tgsv7.nws.noaa.gov/weather/ccworld.html

MPR listener question: This first week of June has been much colder than normal, with snow in northeastern Minnesota. What has been the coldest ever temperature recorded in June? Also, how often does it snow in June?

Answer: According to the Minnesota State Climatology Office database, the coldest June temperature was 15 degrees F at Bigfork (Itasca County) on June 1, 1964. There have been only two other years when temperatures below 20 degrees F have been recorded in June: 1897 at Tower (St Louis County) and 1985 at Remer (Cass County). But, I might add that June frosts in north central and northeastern Minnesota counties are a fairly common occurrence, having been recorded 8 or 9 years out of every ten historically for some communities like Tower. One of the most notable recent June frosts which affected agriculture occurred on the summer solstice in 1992, (June 21) damaging some corn fields.

The number of snowfalls in June is difficult to pin down because the database is somewhat limited. The largest snowfall in June was probably 5 inches on June 1-2, 1945 at Virginia, MN (St Louis County). More recent June snowfalls have occurred in 1969 (nearly an inch at Grand Rapids in Itasca County) and 1985 when a few tenths of inch fell near Babbitt in Lake County). Tuesday of this week (June 2nd) the Forest Service at Isabella (Lake County) reported snowfall at an elevation of about 2000 feet. When June snowfalls occur they are usually in the far north-central or northeastern reaches of the state, but they are far less common than June frosts.

MPR listener question: I read that the National Weather Service said that derechos, straight ahead downburst winds of destructive magnitude like those that occurred Saturday night (May 30th) in the Twin Cities area, are fairly common in Minnesota. Is this true?

Answer: The answer is relative. One or two per year is a fairly high frequency compared to most other places in the United States. Destructive derechos have occurred in Minnesota each of the last six years: July 31, 1993 in southern counties and the metro area; July 5, 1994 in the metro area; July 12-14, 1995 in northern counties; May 18-19, 1996 in the metro area; July 1, 1997 in the metro area; and May 30th of this year. Perhaps the largest of these storms were those which occurred in July of 1995, blowing down over 6.5 million trees in northern Minnesota forests.

Twin Cities Almanac for June 5th:

The average MSP high temperature for this date is 77 degrees F (plus or minus 9 degrees standard deviation), while the average low is 56 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for June 5th:

MSP weather records for this date include: highest daily maximum temperature of 92 degrees F in 1911 and 1925; lowest daily maximum temperature of 50 degrees F in 1935; lowest daily minimum temperature of 41 degrees F in 1894, 1927 and 1935; highest daily minimum temperature of 75 degrees F in 1925; record precipitation of 2.53 inches in 1980.

Average dew point for June 5th is 52 degrees F, with a maximum of 72 degrees F and a minimum of 30 degrees F.

All-time state records for June 5th:

Scanning the state climatic data base: the all-time high for this date is 98 degrees F at Wheaton (Traverse County) in 1939; the all-time low is 18 degrees F at Remer (Case County) in 1985.

Word of the Week: Stacking

This does not refer to the CDs in the MPR music library! In meteorology this term refers to a condition of continuity in the vertical of a low pressure or high pressure system. That is, the geographic center of low pressure at the surface, tends to be the same for low pressure aloft as well. So there is little tilt or horizontal distortion in the pressure field. This may happen with large scale, slow moving low pressure systems and show up in satellite water vapor imagery as a large rotating white blob.

Outlook:

Relatively dry and cool weather should dominate through the weekend and perhaps until Tuesday. Temperatures will average 5 to 10 degrees colder than normal. Beginning about Tuesday of next week, temperatures will warm somewhat near normal, but a series of low pressure systems will bring showers and thunderstorms to the state for much of the second half of the week. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, June 12, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Occult Precipitation

For most parts of the world the atmosphere supplies water to the soil and vegetation by precipitation, in the form of rain or snow. However, in some arid regions occult (or hidden) precipitation is quite important. This refers to atmospheric deposition of water by dew, frost or fog. Climates with high frequency of fog, dew or frost may supply the equivalent of several inches of precipitation during the course of a year or a growing season. Even here in Minnesota, the recent fog and drizzle, though perhaps unrecorded in the rain gage is important to the growth habit of some garden plants and to the longevity that the plant will bear colorful flowers. So even though such conditions in June tend to dampen our spirits, they do have a positive side for some landscape plants.

Topic: The Urban Heat Island Explored by Bicycle

An interesting paper in a recent copy of Weather magazine described the urban heat island of Reading, England as measured by a bicyclist who used a simple digital thermometer with a 10 second response time. He repeatedly cycled 5 mile long transects through the city center near sunset and recorded temperatures along the way about every 1 km. His measurements showed a mean urban heat island effect of about 3 to 4 degrees F, that is the city center tended to be that much warmer than the perimeter areas around the city. Under some conditions, he measured a maximum temperature difference of over 12 degrees F.

His measurements are similar in magnitude to those published by Paul Todhunter concerning the urban heat island effect in the Twin Cities Metropolitan Area. He found a mean annual temperature difference of 3 to 4 degrees F between downtown Minneapolis and the southwestern suburban areas. Further he found a difference of 16 days in the frost-free growing season.

I would be interested to hear from any listeners or readers who routinely bicycle around the Twin Cities area and have found highly perceptible differences in temperature along the routes they take. I would suspect that some city parks and/or city lakes may have some noticeable cooling effects on air temperature, especially in the summer months.

Twin Cities Almanac for June 12th:

The average MSP high temperature for this date is 78 degrees F (plus or minus 7 degrees standard deviation), while the average low is 58 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for June 12th:

MSP weather records for this date include: highest daily maximum temperature of 95 degrees F in 1956; lowest daily maximum temperature of 51 degrees F in 1929; lowest daily minimum temperature of 43 degrees F in 1929; highest daily minimum temperature of 72 degrees F in 1920; record precipitation of 2.35 inches in 1899.

Average dew point for June 12th is 55 degrees F, with a maximum of 74 degrees F and a minimum of 30 degrees F.

All-time state records for June 12th:

Scanning the state climatic data base: the all-time high for this date is 102 degrees F at Crookston (Polk County) in 1893 and at Redwood Falls (Redwood County) in 1956; the all-time low is 23 degrees F at Remer (Cass County) in 1985.

Word of the Week: Blirty

This is not unlike the word "blurt" which refers to a sudden, implusive, and often unexpected verbal response from person. This term is used primarily in Scotland to refer to sudden spells of wind gusts and rain which occur during unsettled highly overcast conditions. Blirty weather certainly fits for many of our early June days in Minnesota this year, some of which have been dominated by spells of rain and cool wind gusts from the north and east. We have seen plenty of clouds, fog, drizzle, rain and wind, along with some record low temperatures already this month.

Outlook:

Low pressure moving out of the central plains will affect Minnesota this weekend bringing a chance for scatter showers and thunderstorms from later in the day Saturday right through early Tuesday. Temperatures will warm up into the 70s and 80s next week, with another chance for showers by Thursday and Friday.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, June 19, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: With several afternoon highs only in the 60s F and a number of nights with minimum temperatures in the 30s F, was the first half of June the coldest ever in the Twin Cities?

Answer: Not quite. According to the MSP climate records, the coldest first half of June (1st through 15th) was in 1945 when the temperature averaged 56 degrees F, or about 10 degrees below normal. The first 15 days of this June (1998) averaged just under 59 degrees F, about 7 degrees below normal, ranking as the second coldest such period in the historical record (back to 1891). I might add that it looks like the daily temperatures will trend toward above normal values for the second half of this month.

Topic: La Nina

After nearly 15 months, El Nino has dissipated, only to be apparently replaced by La Nina. La Nina, meaning little girl, is in many ways the opposite of El Nino. It represents an abnormal cooling in the central and eastern equatorial Pacific Ocean, accompanied by stronger easterly surface winds, and dominance of high atmospheric pressure. Resulting changes in convection, tropical rainfall, and jet stream patterns tend to create some climate anomalies in the tropics and to a lesser degree in some mid latitude locations.

The NOAA Climate Prediction Center forecasts suggest that a full fledged La Nina episode will develop by the fall, too late in the year to have any real impact on the 1998 growing season. As with El Nino most of the unusual climate tendencies seen in Minnesota during La Nina episodes are during the winter months, which tend to be colder than normal. Less is known about the overall climate impacts of La Nina episodes, because there have only been 15 episodes during the 20th century (compared to 23 El Nino episodes). We will undoubtedly hear more about La Nina during the coming year.

More information on La Nina can be found at the following web sites... http://nic.fb4.noaa.gov:80/products/analysis_monitoring/ensostuff/index. html (routine updates from the Climate Prediction Center) http://www.pmel.noaa.gov/toga-tao/la-nina-story.html (Pacific Marine Environmental Lab-Tropical Atmosphere/Ocean Research)

Twin Cities Almanac for June 19th:

The average MSP high temperature for this date is 80 degrees F (plus or minus 8 degrees standard deviation), while the average low is 58 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for June 19th:

MSP weather records for this date include: highest daily maximum temperature of 100 degrees F in 1933; lowest daily maximum temperature of 56 degrees F in 1946; lowest daily minimum temperature of 41 degrees F in 1950; highest daily minimum temperature of 75 degrees F in 1933; record precipitation of 2.44 inches in 1954.

Average dew point for June 19th is 55 degrees F, with a maximum of 76 degrees F and a minimum of 38 degrees F.

All-time state records for June 19th:

Scanning the state climatic data base: the all-time high for this date is 108 degrees F at Beardsley (Big Stone County) in 1933; the all-time low is 26 degrees F at Tower (St Louis County) in 1980 and at Remer (Cass County) in 1985.

Words of the Week: Cold Air Funnels

Cold air funnels are not uncommon in Minnesota, especially in the spring. They are always quite small in scale, short-lived, and hardly ever touch the ground. Unlike tornadoes, whose parent clouds are cumulonimbus (thunderheads) and of great vertical depth, cold air funnels may drop from ordinary cumulus clouds as a result of small scale local instability aloft. They represent cold air eddies and typically appear as small conical shaped protuberances, lasting from seconds to minutes. They are not terribly dangerous, but do contain winds of the same order as dust devils, so they might blow around items like lawn chairs if they do touch down.

Outlook:

Chance of showers and thundershowers each day Saturday through Tuesday. Some possibility for severe weather as well. Daily temperatures will trend above normal, with highs mostly in the 80s. Chance for showers and thunderstorms again toward the end of next week.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, June 19, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: With several afternoon highs only in the 60s F and a number of nights with minimum temperatures in the 30s F, was the first half of June the coldest ever in the Twin Cities?

Topic: La Nina

More information on La Nina can be found at the following web sites...

http://nic.fb4.noaa.gov:80/products/analysis_monitoring/ensostuff/index.html (routine updates from the Climate Prediction Center)

http://www.pmel.noaa.gov/toga-tao/la-nina-story.html

file:///G|/1998/WeatherTalk_1998-06-19.txt[9/22/2015 3:52:06 PM] (Pacific Marine Environmental Lab-Tropical Atmosphere/Ocean Research)

Twin Cities Almanac for June 19th:

The average MSP high temperature for this date is 80 degrees F (plus or minus 8 degrees standard deviation), while the average low is 58 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for June 19th:

Average dew point for June 19th is 55 degrees F, with a maximum of 76 degrees F and a minimum of 38 degrees F.

All-time state records for June 19th:

Words of the Week: Cold Air Funnels

Outlook:

file:///G|/1998/WeatherTalk_1998-06-19.txt[9/22/2015 3:52:06 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, June 26, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: Why all the fires in Florida? I thought that they had plenty of precipitation and storminess earlier this year due to El Nino.

Answer: Indeed, Florida climate stations reported abundant precipitation this winter, but have been quite dry of late. Records for the month of June so far show that many communities have recorded less than 25 percent of normal precipitation. Melbourne and Daytona Beach report only 0.11 and 0.21 inches, respectively for the month of June. The dry conditions have been exacerbated by near record setting high temperatures as well, with daily maximums ranging from 96 to 102 degrees F. The long summer days and high temperatures have caused the Florida landscape and vegetation to dry out very rapidly in some areas.

Topic: Going to the beach this summer?

If you are planning a vacation to coastal beaches this year, the National Oceanic and Atmospheric Administration has a web site for you. Average monthly water temperatures, along with measurements of current conditions, updated each 24 hrs are available for many common beach destinations. You can probably find conditions at your favorite beach at this URL: http://www.nodc.noaa.gov/dsdt/wtg12.html

Topic: Aerosondes help west coast forecasters.

A collaborative effort between the Office of Naval Research and the University of Washington will be initiated this year using remote controlled airplanes (aerosondes) to make weather measurements out over the Pacific Ocean. Ten planes will be used, each approximately 6 feet in length, with a wingspan of 11 feet. Their range will be about 1000 miles (500 miles out and back). Computer controls will guide the planes using satellite-based global positioning systems (GPS).

The data from these planes will supplement data from ships, satellites and commercial aircraft to give west coast forecasters a better assessment of upstream weather conditions and hopefully improve their short term forecasting abilities. (more in the July/August issue of Weatherwise magazine)

Twin Cities Almanac for June 26th:

The average MSP high temperature for this date is 81 degrees F (plus or minus 8 degrees standard deviation), while the average low is 61 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for June 26th:

MSP weather records for this date include: highest daily maximum temperature of 99 degrees F in 1931; lowest daily maximum temperature of 55 degrees F in 1968; lowest daily minimum temperature of 46 degrees F in 1926; highest daily minimum temperature of 78 degrees F in 1931; record precipitation of 2.10 inches in 1914.

Average dew point for June 26th is 58 degrees F, with a maximum of 74 degrees F and a minimum of 38 degrees F.

All-time state records for June 26th:

Scanning the state climatic data base: the all-time high for this date is 106 degrees F at Milan (Chippewa County) in 1933; the all-time low is 30 degrees F at Fosston (Polk County) in 1929 and at Tower (St Louis County) in 1982.

Word of the Week: Fulgurite

This word is used by both geologists and meteorologists. Derived from the Latin root word "fulgur", meaning lightning, this is a term used for the glassy, rootlike tube that is formed when lightning strikes a sandy soil. The intense heat causes soil moisture to vaporize, and the remaining molten material fuses into a tube like structure which may be an inch or two in diameter and inches to several feet in length. The wall-like material holding them together is very thin and fragile, so they typically crumble and fall apart when dug up. Recently University of Florida lightning researchers reported finding a fulgurite with three branches, one of which extended 16 ft into the soil. This was noted as a world record size for fulgurite. (more on this in the July/August Issue of Weatherwise magazine)

Outlook:

Chance of showers and thunderstorms Saturday through Monday. Very warm temperatures with some 90 plus readings around the state, along with higher muggy dew points. Somewhat cooler by the middle of next week, but temperatures will likely remain a few degrees above normal through the end of the week. Chance of showers returning by mid week.

To: Perry Finelli, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, July 3, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Heavy Rains and the June 1998 Climate Summary

A series of heavy thunderstorms drenched southeastern Minnesota counties last week. Some parts of Scott, Rice, and Goodhue counties received over 8 inches and Zumbrota reported over 10 inches. These heavy rains swelled the Zumbro, Cannon, Root, and Iowa Rivers to near flood stage, but they rapidly receded by Monday. Many east central and southeastern Minnesota communities recorded above normal rainfall for June. Hastings and Wabasha recorded new June rainfall records with 9 inches. Western and northern counties generally received less than normal June rainfall. Statewide, June temperatures averaged 2 to 4 degrees colder than normal, thanks mainly to an extremely cold first half of the month when some frosts were reported.

MPR listener question: Severe weather continues to make the headlines each week. This week, Iowa was hit with numerous severe thunderstorms and at least 4 tornadoes. What has been the worst tornado outbreak recorded in the United States?

Answer: Perhaps the two worst tornado outbreaks in the United States this century occurred in the springs of 1925 and 1974. The first was a highly destructive and long-lived single tornado, while the latter was an outbreak of mulitple tornadoes, perhaps the most ever recorded in a 24 hour period.

On March 18, 1925 the famous Tri-State Tornado crossed Missouri, Illinois and Indiana. This was a single tornado which stayed on the ground for over three and one half hours, traveling nearly 220 miles. It caused 695 fatalities, over 2000 injuries, and over $200 million in property damages. This tornado would likely have caused more death and destruction had it passed over more highly populated cities, but it encountered mostly rural areas.

On April 3-4, 1974 in a sixteen hour period, 147 tornadoes were reported in a ten state area, centered around Indiana and Kentucky. Though most of these tornadoes were relatively weak and short-lived, some were quite severe, such as the one which destroyed Xenia, Ohio. Total fatalities from this outbreak were 335.

Some July 4th Trivia:

How often does it rain in the Twin Cities on July 4th? (Answer: about 44 percent of the time since 1891)

What was the warmest 4th of July in the Twin Cities? (Answer: Afternoon high of 100 degrees F in 1949)

What was the coldest 4th of July in the Twin Cities? (Answer: Afternoon high of only 58 degrees F in 1967)

Twin Cities Almanac for JuLy 3rd:

The average MSP high temperature for this date is 82 degrees F (plus or minus 8 degrees standard deviation), while the average low is 62 degrees F (plus or minus 6 degrees standard deviation).

MSP Local Records for July 3rd:

MSP weather records for this date include: highest daily maximum temperature of 100 degrees F in 1949 and 1990; lowest daily maximum temperature of 62 degrees F in 1927; lowest daily minimum temperature of 47 degrees F in 1967; highest daily minimum temperature of 79 degrees F in 1949; record precipitation of 2.40 inches in 1903.

Average dew point for July 3rd is 59 degrees F, with a maximum of 77 degrees F and a minimum of 44 degrees F.

All-time state records for July 3rd:

Scanning the state climatic data base: the all-time high for this date is 107 degrees F at Beardsley (Big Stone County) in 1949; the all-time low is 29 degrees F at Meadowlands (St Louis County) in 1927.

Word of the Week: Birainy

This is a term used in climate classification to refer to a place on Earth that has two distinct rainy seasons within a year. Most often these are locations near the equator which measure more abundant rainfall at or shortly after the equinoxes (March and September), a period of high sun. Some equatorial African countries and equatorial South American countries have such climates, including Zanzibar (east Africa) and Bogota (Columbia). Tropical rain forest vegetation thrives in this type of climate.

Outlook:

High pressure will keep the weather mostly sunny and pleasant for the 4th of July weekend, until later in the day on Sunday when there will be a chance for showers. A warming trend will start next week, taking temperatures to a few degrees above normal. Increasing chance for showers and thunderstorms by Monday and Tuesday and again Friday and Saturday. Dew points will be on the rise and will reach uncomfortable levels for a few days.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, July 10, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Women in Meteorology

WWII brought about a remarkable change in the gender distribution among professional meteorologists and weather observers. Staff shortages and an expansion of weather observing and forecasting programs in both European countries and the United States helped open the doors for women to enter the field of meteorology. Historical analysis has shown that female observers and forecasters were extremely valuable to the weather services of the United States, England and Russia during this time. The British Meteorological Office affectionately referred to their WWII female forecasters as the Met Queens, one of whom (Ingrid Holford) later became a well-known television forecaster for Southern TV in the United Kingdom. The Weather Service in the United States employed only two women in the observer and forecaster ranks in 1941, but by 1945 over 900 were working in such capacities. Many went on to have long careers with the Weather Service.

Today, the World Meteorological Organization reports that there are far more female students of meteorology than ever before, and they anticipate that the percentage of women in the profession will be going up. Worldwide, it is estimated that about 20 percent of all meteorologists and hydrologists are women. Women comprise about 9 percent of the American Meteorological Society membership in the United States. There is great variability in these numbers from country to country. In some of the former republics of the Soviet Union and eastern European countries (including Kazakstan, Ukraine, and Latvia) 60 to 80 percent of professional meteorologists and hydrologists are women.

Here in Minnesota, NOAA weather radio listeners are very familiar with the observations and forecasts given by the pleasant voice of Kathy Erickson, who has worked for the local National Weather Service Forecast Office in the Twin Cities for over 25 years.

Topic: Weather and the CEO

One of the skills of company executives is to blame poor quarterly profits on fickle weather conditions. One of the most imaginative weather excuses came from a South African executive whose cat litter business was suffering from poor sales. He found blame due to a prolonged dry spell of weather which meant that cats were spending more of their time outdoors. (from: Weather, vol. 46, 1991).

Twin Cities Almanac for July 10th:

The average MSP high temperature for this date is 83 degrees F (plus or minus 8 degrees standard deviation), while the average low is 63 degrees F (plus or minus 6 degrees standard deviation).

MSP Local Records for July 10th:

MSP weather records for this date include: highest daily maximum temperature of 106 degrees F in 1936; lowest daily maximum temperature of 69 degrees F in 1945; lowest daily minimum temperature of 49 degrees F in 1945 and 1996; highest daily minimum temperature of 80 degrees F in 1936; record precipitation of 1.15 inches in 1984.

Average dew point for July 10th is 59 degrees F, with a maximum of 79 degrees F and a minimum of 42 degrees F.

All-time state records for July 10th:

Scanning the state climatic data base: the all-time high for this date is 111 degrees F at Beardsley (Big Stone County) and Campbell (Wilkin County) in 1936; the all-time low is 32 degrees F at Tower (St Louis County) in 1978.

Community Salute: Wadena, MN

The county seat of Wadena County in central Minnesota, this community got its name from the Ojibway Indian word meaning "little round hill." It was originally a trading post along the Red River Ox Cart Trail. The city of Wadena is the only climate station with any longevity in the county. The first observer there was Mr. B.F. Buck, Jr who began taking daily observations of the weather for the Army Signal Corps in March of 1885. Numerous others have contributed to the daily climate record which is over 100 years old.

Wadena County produces corn, hay, and edible beans, some of which are grown on irrigated sandy soils. The average frost-free growing season is about 135 days long. Some historical climate extremes recorded there include: a maximum temperature of 112 degrees F on July 10, 1936; a minimum of -43 degrees F on February 2, 1996; rainfall of 6 inches on August 7, 1995; and snowfall of 20 inches on March 15, 1957. The driest year on record was just 13.42 inches of precipitation in 1976, and the wettest 1965 with 38 inches.

Wadena is one of the host cities this year for the 9th Annual MS Tram across Minnesota (bicycle tour) to benefit the Multiple Sclerosis Society. With perhaps as many as 2000 bikers passing through on July 28th, let's hope that Wadena enjoys a fair weather day.

Word of the Week: Phreatophytes

Derived from the Greek word "phreatos" meaning well or underground water, this terms refers to types of plants with extensive root systems that utilize water from the underlying water table. These plants generally have adapted to more arid climates in establishing powerful root systems which can lift water from great depths. The root systems of some phreatophytes have been traced to depths of over 45 feet. Greasewood, mesquite, willow, and alfalfa, among others are considered phreatophytes.

Outlook:

Warming trend underway and continuing next week, as temperatures will average above seasonal normals. Chance for widely scattered showers and thunderstorms in northern counties Saturday through Monday. Winds will generally be light and variable during this period. Some 90 plus degree temperatures may occur in parts of southern Minnesota, especially towards the end of next week. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, July 17, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: I read in the paper that in the summer of 1993, the Twin Cities did not record a single temperature of 90 degrees F or higher. Had this ever happened before?

Answer: Yes, since 1891 there have been three summers in the Twin Cities when temperatures never reached 90 degrees F. They were 1902, 1915, and 1993.

Topic: Twin Cities Forecaster Helps Fight Florida Fires

Minnesota firefighters are not the only people helping in Florida. Byron Paulson, a lead forecaster with the National Weather Service Forecast Office in Chanhassen, MN has been temporarily reassigned to help fight the wildfires in Florida. With a mobile forecasting unit (which includes a laptop computer for Internet access, small radio and satellite antennas, and remote weather stations), he is assisting fire fighting operations in a fire camp near Bunnell just north of Daytona Beach. He provides current weather information and updated forecasts, working a 16 hour day (5 am to 9 pm) as an incident meteorologist on special emergency duty. He says that recent rains have greatly assisted the fire fighting, as some crews are being sent home this week.

Readers or listeners who wish to stay updated on the fire situation in Florida might want to check out the NOAA web site: http://www.ncdc.noaa.gov/ol/climate/research/1998/fla/florida.html

Topic: Summer Heat

The Heat Index (combination of temperature and humidity) reached values of 100-110 earlier this week around the state, prompting the National Weather Service to issue heat advisories as part of their daily forecasts. The St Paul Pioneer Press carried an article that commented about how unusual this was since the decade of the 1990s has been dominated by cooler than normal summers in Minnesota. This was based on the number of days with temperatures of 90 degrees F or higher. Indeed, the average number of days with temperatures of 90 F or higher is 15 in the Twin Cities record, but this has been exceeded only once so far this decade, in 1995 when 18 such days were recorded.

Taking a different perpsective, I examined the mean summer temperatures (June through August) to see how each summer since 1990 ranked in the historical record. The table below shows the rankings for Minnesota, Missouri, Ohio and the entire midwest (a 9 state aggregate including MN, IA, MO, IL, IN, WI, MI, OH, and KY). Averages were computed from all locations with daily climate observations. Both Minnesota and the 9 state midwest data show that 1991 and 1995 summers were clearly warmer than normal, falling in the warmest 30 percent historically. The data also show that summer of 1992 was uniformly one of the coolest in the region. The tabular data illustrate that warmer or cooler summer temperatures are not closely associated with warmer or cooler annual temperatures. Categorically, the only consistent year, in the midwest was 1991 which proved to be a warmer than normal summer and warmer than normal year.

The lack of consistency between summer temperature departures and annual temperature departures is explained in part by the fact that it is the winter months in the midwest that tend to be more highly variable and contribute more significantly to variations in the annual temperature state by state.

Table: Ranking* warm summers (Jun-Aug) and warm years (Jan-Dec) in the midwest since 1990 using the base period of 1895-1997 and calculated aggregate mean temperatures for each state.

SUMMERS: Location Coolest 30 pct Warmest 30 pct Near-Normal Minnesota 1992, 1993, 1994 1991, 1995 1990, 1996, 1997 Missouri 1992, 1997, 1994 1991 1990, 1993, 1995, 1996 Ohio 1992, 1997 1995, 1991 1993, 1994, 1996, 1990 Midwest 1992, 1997, 1996 1995, 1991 1990, 1993, 1994

YEARS: Location Coolest 30 pct Warmest 30 pct Near-Normal Minnesota 1996, 1993 1991, 1990 1992, 1994, 1997, 1995 Missouri 1996, 1993, 1997 1990, 1991 1992, 1994, 1995 Ohio 1996, 1997 1991, 1990 1993, 1994, 1992, 1995 Midwest 1996, 1993, 1997 1990, 1991 1994, 1992, 1995

*Coolest and warmest 30 percent are based on this historical distributions of summer and annual temperatures since 1895.

Twin Cities Almanac for July 17th:

The average MSP high temperature for this date is 83 degrees F (plus or minus 7 degrees standard deviation), while the average low is 64 degrees F (plus or minus 6 degrees standard deviation).

MSP Local Records for July 17th:

MSP weather records for this date include: highest daily maximum temperature of 99 degrees F in 1936; lowest daily maximum temperature of 66 degrees F in 1939; lowest daily minimum temperature of 52 degrees F in 1937 and 1976; highest daily minimum temperature of 79 degrees F in 1936 and 1942; record precipitation of 3.71 inches in 1997.

Average dew point for July 17th is 62 degrees F, with a maximum of 76 degrees F and a minimum of 46 degrees F.

All-time state records for July 17th:

Scanning the state climatic data base: the all-time high for this date is 110 degrees F at Worthington (Nobles County) in 1936; the all-time low is 33 degrees F at Bigfork (Itasca County) in 1971.

Community Salute: Ely and Winton, MN

Located at the termination of Hwy 169 in northeastern Minnesota, these communities lie along the border of Lake and St Louis Counties just south of the Boundary Waters Canoe Area. The Iron Range lies to the west and Superior National Forest to the north, south and east.

As one of the few long term climate stations in the northeast, the Ely-Winton records have been used to help quantify the climate of Superior National Forest, providing much needed information to forest and wildlife managers in the area.

The first observer there was the Reverend William Farrell, who started daily observations of temperature and rainfall at Ely in March of 1911. Until recently, the personnel at the Ranger Station in Ely and the Power Plant in Winton took daily observations. Since 1997, the weather observer has been Peter Doran.

Some climate statistics for the Ely-Winton area: frosts have occurred well into June, but never in July. The all-time highest temperature in the area was recorded on June 19, 1995 when the mercury reached 100 degrees F; the all-time lowest temperature was -45 degrees F on February 12, 1967; heaviest rainfall was 4.83 inches on May 20, 1970; longest dry spell was 36 days without rain from March 23 to April 27, 1984; longest wet spell, 15 consecutive days with rain from June 5 to 19, 1915; longest severe cold wave, 10 straight days with the temperature remaining below 0 degrees F, January 18-27, 1963.

Words of the Week: Thermal Equator

This is different from the geographic equator which circumscribes the Earth at 0 degrees latitude. The thermal equator is a line which circumscribes the Earth connecting all points of highest annual mean temperature. Its course varies with the continents and ocean currents and rarely runs parallel to the geographic equator. For example in the western hemisphere it ranges from nearly 20 degrees north latitude across Mexico to 14 degrees south latitude across parts of Brazil.

Outlook:

Temperatures will continue to be near or above normal for this time of year under mostly sunny skies. A chance for showers and thunderstorms spreading across the state Sunday and Monday, otherwise a quiet week with warm temperatures coming up. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, July 24, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Recent Evaluation of the Cooperative Observer Program

A recent report by the National Research Council evaluated the National Weather Service Cooperative Observer Program. This program has been in existence since the 1890s, when the agency was first created under the Department of Agriculture.

Through this program thousands of volunteers monitor daily weather conditions including daily maximum and minimum temperatures, and precipitation. These data are used by state and federal agencies in a variety of ways - to make forecasts, monitor water resources, and track environmental changes for example. Many businesses also utilize these data - to assess snowloads on buildings, estimate energy demand for heating and cooling, and evaluate the adaptability of new crops in agricultural regions.

The report highlights flaws and inefficiencies in the present system including obsolete equipment, slow data reporting, poor use of modern communications and computer technologies, and inadequate resource allocation for maintaining the network and giving feedback to the volunteer observers. Of the over $4 billion dollars spent on the National Weather Service modernization in recent years, less than $10 million each year is allocated for the Cooperative Observer Program. The National Research Council panel recommended increased funding for this program, greater deployment of new equipment, and more widespread use of modern digital communications systems to bring the observations into the daily data stream available via satellite and the Internet. They also recommended greater cooperation among users of the data (including government agencies and private businesses) in setting priorities, uniform policies, and perhaps creating a fee structure for the data in order to help recover costs.

This topic will be discussed further at the Annual Meeting of the American Association of State Climatologists in Duluth, MN, August 5-8, 1998.

Topic: Professor Lewis F. Richardson, non-conformist

One of the pioneers in numerical weather prediction in the early 20th century (using the equations of fluid dynamics to solve for motions and turbulent flows in the atmosphere), Professor Richardson was one of the most esteemed members of the British Meteorological Office. Before computer technology was available, Professor Richardson proposed that numerical weather predictions could be made using scores of desk top calculators to solve the basic equations of atmospheric motions. A highly religious man, he was a conscientious objector during WWI and served in an ambulance unit in France from 1916-1919. Described as short-tempered and without respect for authority, he was considered a maverick in the British scientific community.

In 1920, he resigned from the Meteorological Office when it became part of the Air Ministry and somewhat more dedicated to supporting military operations. Losing his research talents was a bitter blow to the Meteorological Office. Richardson spent the rest of his career primarily as a teacher and a researcher who attempted to model the statistics of war. In later life he wrote two books on war and peace. He died in 1953, but today there is a Richardson Institute for Conflict and Peace Research which helps carry on his work.

Topic: Archaeology Confirms Climatology

Excavations along the Nile Delta in Egypt have revealed a number of prehistoric villages, dating back to around 4000 BC, the Egyptian Neolithic period when tools and wares were made of stone. A series of oval or horseshoe-shaped structures were found somewhat randomly spaced and without common orientation. These roofless huts had walls made of wattle (woven twigs), and were likely used for storage of grain and as pens for small animals. They were also probably used for shelter from the wind. Climatologists have found that the common orientation of the doorless entrance on the southeast facing side conforms to the wind direction of least frequency and is diametrically opposite to the direction of the strongest windstorms in the region which come out of the northwest. Thus, the choice of direction for the opening of these huts was clearly based on a perception of the wind climatology in the Nile Delta region, assuming that the frequency distribution of the wind has changed little over the millenia.

Twin Cities Almanac for July 24th:

The average MSP high temperature for this date is 84 degrees F (plus or minus 7 degrees standard deviation), while the average low is 64 degrees F (plus or minus 6 degrees standard deviation).

MSP Local Records for July 24th:

MSP weather records for this date include: highest daily maximum temperature of 104 degrees F in 1941; lowest daily maximum temperature of 65 degrees F in 1911 and 1915; lowest daily minimum temperature of 49 degrees F in 1891; highest daily minimum temperature of 78 degrees F in 1934; record precipitation of 1.44 inches in 1985.

Average dew point for July 24th is 61 degrees F, with a maximum of 75 degrees F and a minimum of 39 degrees F.

All-time state records for July 24th:

Scanning the state climatic data base: the all-time high for this date is 110 degrees F at New London (Kandiyohi County) in 1901 and at Canby (Yellow Medicine County) in 1940; the all-time low is 35 degrees F at Angus, Hallock, and Roseau (all NW Minnesota) in 1913.

Word of the Week: Elfin Forests

This term is taken from the old Middle English word "elvene" meaning elf-like, small and sprightly. It is used to describe forests which grow in harsh environments, typically windblown, perhaps at high elevation, often dry and in very shallow or rocky soils. Many of the world's mountain ranges have elfin forests. Only dwarf trees can grow and they appear gnarled and misshapen, bearing little resemblance to members of the same species that grow in more favorable environments. The bristlecone pine that grows in Colorado is such a species. In parts of South America they call the elfin trees the Ceja de la Montana, meaning eyebrow of the forest.

Outlook:

High pressure will bring a pleasant weekend to Minnesota. Light winds, somewhat cooler than normal temperatures, low dewpoints, and sunny skies will be in order. A low pressure system will bring clouds and a chance for showers from late Sunday to perhaps early Tuesday. Then another chance for showers by Thursday evening.

To: Perry Finelli, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, August 7, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Preliminary Climate Summary for July 1998:

The average July temperature reported by climate observers around the state was very close to the long term normal. Most observers reported a drier than normal month, with some notable exceptions. Alexandria reported over 5.5 inches of rainfall for the month, while Itasca State Park reported over 5 inches. After frequent spells of severe weather in May and June, July was a quieter month.

Topic: American Association of State Climatologists

The American Association of State Climatologists are holding their annual meeting in Minnesota this year. The meeting is being conducted at the Duluth Radisson from August 5-8. Many of the leading climatologists in the United States will be there discussing global warming, climate extremes, urban and agricultural climatology, and the modernization of the National Weather Service. To find out more about this organization and what they do, you can go to the following web site.... http://www.ncdc.noaa.gov/ol/climate/aasc.html

Topic: Natural Hazards

There is an excellent article on natural hazards, along with a map supplement in the July issue of National Geographic magazine. The article features statistics, historical perspectives, scientific findings, and excellent illustrations on earthquakes, floods, hailstorms, hurricanes, landslides, tornadoes, tsunamis, volcanic eruptions, wildfires, and winter storms. The article also points out that shifts in North American's population during the second half of the 20th century have exposed more people to the threat of natural hazards and caused an almost exponential increase in insurance claims. For example, the average number of hailstorms has remained somewhat stable over the decades, but increasing population density in hail prone areas has contributed to escalating damage claims. Property damage from hailstorms is now on par with crop damage. The combined total of these damages is now estimated to average $2.3 billion per year in the United States. More information from the National Geographic Society is available on their web site at..... http://www.nationalgeographic.com

MPR listener question: What is the coldest August temperature for the Twin Cities and how cold does it get during the month in northern Minnesota?

Answer: The MSP records, dating back to 1891, show that the coldest reading in August was 39 degrees F on August 19, 1967. Low temperatures in the 20s and 30s during August are far more frequent in northern counties. The coldest I could find in the state climate records was 21 degrees F at Tower, MN on August 28, 1986. Twin Cities Almanac for August 7th:

The average MSP high temperature for this date is 82 degrees F (plus or minus 8 degrees standard deviation), while the average low is 62 degrees F (plus or minus 6 degrees standard deviation).

MSP Local Records for August 7th:

MSP weather records for this date include: highest daily maximum temperature of 97 degrees F in 1949 and 1983; lowest daily maximum temperature of 61 degrees F in 1917; lowest daily minimum temperature of 45 degrees F in 1972; highest daily minimum temperature of 74 degrees F in 1930 and 1937; record precipitation of 2.29 inches in 1984.

Average dew point for August 7th is 60 degrees F, with a maximum of 74 degrees F and a minimum of 42 degrees F.

All-time state records for August 7th:

Scanning the state climatic data base: the all-time high for this date is 104 degrees F at Alexandria (Douglas County) in 1983; the all-time low is 29 degrees F at Brimson (St Louis County) in 1989.

Word of the Week: Isoerodent

This is not a type of rodent, nor is it a meteorological term. It is a term from soil science and means a line connecting points on a map which have an equal erosivity index. The average erosivity of soils (loss of soil in sediment runoff) is computed from the Universal Soil Loss Equation partially based on the long term historical rainfall and rainfall intensity. Many other soil characteristics are considered as well. The relative differences in the erosivity index across a landscape can be compared by mapping these values using isoerodents (lines of equal value).

Outlook:

Though the first week of August has brought below normal temperatures, a warming trend will begin this weekend and last through much of next week. Daytime highs will be in the 80s most places. Chance for showers in the southern counties on Saturday, mostly dry up north. Another chance for showers in southern Minnesota by the middle of next week. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, August 21, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Rochester Tornado Anniversary

One hundred fifteen years ago today, Rochester, MN was struck by an F5 tornado. Thirty people were killed, 200 were injured, and over 1300 buildings were damaged or destroyed. The recovery and first aid efforts helped form the foundation for the establishment of the cities first hospital, St Marys, where the Mayo brothers began their medical practice which was to lead to eventually lead to the Mayo Clinic. A tornado of similar intensity has yet to revisit the Rochester area.

Topic: Distinguishing Normal from Average

These terms are often confused by the public when listening to meteorologists or climatologists. The term "normal" refers to a mandated set of 30 year climate averages for the preceding 3 complete decades of data. This is a international standard set by the World Meteorological Organization. The current reference normals, whether monthly or daily values, are derived from the 1961-1990 period. However, the use of the term normal sometimes implies two false perceptions: (1)that the normal value of a climate parameter (temperature or precipitation for example) is the most common one historically; and (2) that large deviations from these normal values are abnormal. These perceptions may be true for some of the world's climates, such as coastal or equatorial locations, but they are certainly not correct for the upper midwest, where large climate variations are quite common. For example, the normal high and low temperatures in the Twin Cities for today's date (August 21) are 80 and 61 degrees F, respectively. Yet, checking the historical records back to 1891 (a 107 year period), the high temperature has been 80 degrees F on this date only 7 times and the low has been 61 degrees F only twice. The current 30 year normal for August rainfall in the Twin Cites is 3.62 inches, a value which has never occurred in the 107 year record primarily because the standard deviation for August rainfall is plus or minus 2 inches.

Average values may refer to almost any time period of climate. When meteorologists and climatologists refer to average values it is necessary to define the period of record, because it may vary considerably from 10 to 100 years or more. In comparing daily or monthly climate averages from location to location, it is important to use equal periods of record. This is also true in climate change research, which often compares year to year composite or aggregate means of temperature to some historical average. Some climate researchers were initially criticized for using the 1951 to 1970 period as a base reference for average monthly and annual temperatures, instead of the recent 30 year normal period (1961-1990) or a 100 year averaging period which captured more variation.

Though averages continue to be used to compare climates, it is important to remember that the distribution of values from which the averages are computed may be quite different from one time period to another, or from one location to another.

MPR listener question: I have been hearing more and more about how dry August has been in parts of Minnesota. What is the driest August in the state climate records?

Indeed, many parts of the state have received less than a third of inch of rainfall this month, though Wednesday nights thunderstorms dropped 0.5 to 1.0 inches on many central and western communities, and up to 3-4 inches in parts of Pope, Douglas and Swift Counties. Where it remains dry, shallow rooted pasture lands are suffering, but deep rooted crops seem to be OK, relying on the stored soil moisture deeper in the rootzone.

The driest August on a statewide basis was in 1930, when the average rainfall for all reporting communities was just over one inch. The driest August for an individual community was probably Beardsley in west-central Minnesota (Big Stone County), which recorded only 0.01 inches in 1969. The driest August in the Twin Cities climate record was 1925, with only 0.20 inches.

Twin Cities Almanac for August 21st:

The average MSP high temperature for this date is 80 degrees F (plus or minus 7 degrees standard deviation), while the average low is 61 degrees F (plus or minus 6 degrees standard deviation).

MSP Local Records for August 21st:

MSP weather records for this date include: highest daily maximum temperature of 98 degrees F in 1947; lowest daily maximum temperature of 59 degrees F in 1966; lowest daily minimum temperature of 50 degrees F in 1920 and 1956; highest daily minimum temperature of 74 degrees F in 1968; record precipitation of 3.64 inches in 1924.

Average dew point for August 21st is 58 degrees F, with a maximum of 76 degrees F and a minimum of 34 degrees F.

All-time state records for August 21st:

Scanning the state climatic data base: the all-time high for this date is 103 degrees F at Moorhead (Clay County) in 1947 and at Milan (Chippewa County) in 1976; the all-time low is 28 degrees F at Tower (St Louis County) in 1986.

Word of the Week: WOCE

This is another scientific acronym and stands for the World Ocean Circulation Experiment, a multi-national research effort carried out under the World Climate Research Programme. The experiment essentially ended this summer, but it will take many years to analyze all of the data. Instrumented ships, buoys, and floats provided measurements of many physical and chemical characteristics related to ocean circulation patterns. In addition to meteorological measurements of atmospheric conditions, measurements were made of ocean temperature with depth, velocity of ocean currents, depth of mixing layers, salinity, oxygen, carbon dioxide, and other chemical constituents. These data will be used in conjunction with satellite data to better understand the interactions of ocean circulation patterns with the Earth climate system.

Those wishing to find out more details about this experiment and the available data sets can browse the National Oceanographic Data Center web site on the Internet at.... http://www.nodc.noaa.gov

Outlook:

Chance of showers and thunderstorms Saturday and Sunday, especially in southern Minnesota counties. Mostly dry up north. Temperatures will cool down to near average values next week and dewpoints will be lower and more comfortable as well. Daytime highs will be mostly in the 70s and overnight lows mostly in the 50s. Conditions for the opening of the State Fair next week should be near normal temperatures with a 30 to 40 percent chance of scattered showers. To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, August 28, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Minnesota Public Radio Weather Quiz for the 1998 State Fair (Take a guess at these questions used on the August 27th Midday Program from the State Fair and check the answers below)

1. What is the most total snowfall recorded for a single snow season (Sept-May) in Minnesota? Where and when did it occur?

2. What is occult precipitation? a. precipitation that occurs at night b. an underground irrigation system c. tree sap d. moisture from dew, frost, or fog

3. What is the largest change in temperature recorded in a 24 hour period in Minnesota? Where and when did it occur?

4. Who is the current Director of the National Weather Service?

5. In what year did Minnesota record the greatest number of confirmed tornadoes? What was the number?

6. In the Twin Cities metropolitan area what is the simplest, quickest, and most accurate source of weather information? (Aside from MPR of course!)

7. What has been the highest dewpoint measured during the State Fair?

8. Based on climatology, during the 12 days of the State Fair, how many days does it rain?

9. What is Fulgurite? a. Gary Eichten's favorite imported beer b. A sandy tube like structure formed from a lightning strike c. A weather sealant to paint on decks d. A torch used to illuminate caves

10. What is the greatest amount of snowfall in one month recorded in the Twin Cities?

Answers: 1. Winter 1995-1996 at Lutsen, MN with 153.9 inches of snowfall. 2. d 3. April 3, 1982, following an afternoon high of 78 degrees F the temperature dropped to 7 degrees F at Lamberton, MN, a 71 degree F temperature change. 4. General John (Jack) Kelly, former head of the Air Force Weather Service 5. 47 tornadoes were confirmed in both 1993 and 1997. 6. NOAA Weather Radio, broadcasting from the National Weather Service Forecast Officed in Chanhassen, 24 hr per day, KEC 65 at 162.55 Mhz) 7. A very sticky 77 degrees F on August 28, 1955. 8. 3-4 days on average 9. b, when lighnting strikes a sandy soil, fulgurite often forms 10. November, 1991 with 46.9 inches (starting with the famous Halloween Blizzard that year).

Topic: Weather Forecasting Rules of Thumb

I often get asked about simple forecasting rules that might be used to anticipate weather conditions when radio and television information sources are not available. Each forecaster probably has his or her own rules of thumb, but some of the more common ones are....

Clear skies, low humidity and calm winds shortly after sunset produce very low overnight minimum temperatures and by late September or early October lead to frosts.

Towering cumulus clouds by mid morning can be an indicator of a stormy afternoon.

Conversely, the dissipation of overnight fog by mid morning usually ushers in a fair weather afternoon.

The dewpoint shortly after sunset is an indicator of the potential overnight minimum temperature.

When outdoors, stand with your back to the wind. Low pressure will be on your right and high pressure on your left. Remember that pressure systems often migrate from west to east in Minnesota.

Counterclockwise wind shifts usually usher in colder and drier air.

MPR listener question: I read earlier this week that Del Rio, TX received nearly 18 inches of rain in a 24 hour period as a result of Tropical Storm Charley. This produced a severe flash flood in the Rio Grande watershed. Is that a record amount of rainfall for 24 hours?

Answer: NO! Far from it. The record 24 hour rainfall is 43 inches at Alvin, TX on July 26, 1979. This is about 300 miles due east of Del Rio and lies on the Galveston Bay drainage area. The threat of flashflooding from such rains is more serious in the hilly topography and landscape around Del Rio than it is in the flatlands around Alvin. Incidentally, the record rainfall in Alvin, TX was a result of Tropical Storm Claudette coming ashore near Galveston.

Twin Cities Almanac for August 28th:

The average MSP high temperature for this date is 78 degrees F (plus or minus 9 degrees standard deviation), while the average low is 59 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for August 28th:

MSP weather records for this date include: highest daily maximum temperature of 94 degrees F in 1899 and 1955; lowest daily maximum temperature of 61 degrees F in 1935; lowest daily minimum temperature of 42 degrees F in 1934; highest daily minimum temperature of 75 degrees F in 1969; record rainfall of 1.11 inches in 1950.

Average dew point for August 28th is 59 degrees F, with a maximum of 77 degrees F and a minimum of 34 degrees F.

All-time state records for August 28th:

Scanning the state climatic data base: the all-time high for this date is 104 degrees F at Canby (Yellow Medicine County) in 1937; the all-time low is 21 degrees F at Tower (St Louis County) in 1986.

Words of the Week: storm surge, swash, and backwash

These terms all refer to actions of ocean waters as they erode shorelines and beaches. A storm surge is produced by the wind action of large storms such as hurricanes. They literally push water up on shore and inland beyond the limits of normal tidal actions. Swash is the action produced by waves as they intermittently break across shorelines and beaches, while backwash is the return flow of water back to the sea. The combined erosive effects of these actions can be quite destructive, depending on their intensity and duration. Because of its relatively slow movement, Hurricane Bonnie may produce long lasting erosive effects along North Carolina's seacoast.

Outlook:

Pleasant, comfortable weather statewide for the weekend and early next week. Temperatures near seasonal normals much of the time, then warming toward the Labor Day weekend with an increasing chance for showers and thunderstorms by Sept 3rd.

To: Bob Potter, Jim Bickal, John Bischoff, and Stephanie Curtis From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Sept 4, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Smoke and Haze from Fires

Earlier this week, Bob Weisman, a meteorology Professor at St Cloud State reported reduced visibility in central Minnesota counties as a result of smoke and haze coming from forest fires and wildfires in northeastern Alberta and northwestern Saskatchewan. A dry summer in the prairie provinces of Canada along with a recent high frequency of lightning strikes from thunderstorms produced numerous fires which burned over 300,000 acres in Alberta. Smoke from these fires was even visible in satellite imagery on Tuesday and Wednesday of this week. The smoke plume from these fires was carried over North Dakota and Minnesota by a migrating high pressure system. The light winds and stable air mass helped keep the smoke plume in tact. It is more common for such smoke plumes to be carried long distance by high pressure systems rather than low pressure systems. The turbulence, instability, cloud cover and rainfall associated with low pressure systems dilute, disguise and washout smoke plumes such that they don't travel very far. Thus, in Minnesota we are exposed to fire generated smoke and haze from the west or northwest when migrating high pressure cells coincide with the occurrence of such fires.

Topic: Water Quality and Agricultural Drainage

A recent report from Ohio State University highlights some research findings pertaining to agricultural drainage. The report summarizes the work of several midwestern states through the USDA sponsored project known as Management Systems Evaluation Areas (MSEA). The Minnesota section of the report offers some insights into climate, drainage and cropping systems..

When wet years follow dry years, a substantial amount of nitrate N from soils that are high in organic matter is susceptible to loss in subsurface drainage. This can occur even in the absence of applied nitrogen fertilizer, though the rate and timing of applied nitrogen fertilizer affects the amount of nitrate N detected in subsurface drainage water.

A long term increase in average annual precipitation is detectable in the climate records of many Minnesota counties. The floods of 1993 and 1997 were primarily climate driven. Drainage impacts on these floods are difficult to quantify, but are being investigated.

The trend toward increased precipitation has coincided with an increase in soil compaction problems, which restrict water flow within the soil and limit root growth. These compaction problems can be reduced by subsurface drainage tiles in many agricultural soils.

Twin Cities Almanac for Sept 4th:

The average MSP high temperature for this date is 77 degrees F (plus or minus 9 degrees standard deviation), while the average low is 56 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for Sept 4th:

MSP weather records for this date include: highest daily maximum temperature of 98 degrees F in 1925; lowest daily maximum temperature of 59 degrees F in 1920; lowest daily minimum temperature of 39 degrees F in 1974; highest daily minimum temperature of 73 degrees F in 1960; record rainfall of 2.08 inches in 1911.

Average dew point for Sept 4th is 55 degrees F, with a maximum of 74 degrees F and a minimum of 35 degrees F.

All-time state records for Sept 4th:

Scanning the state climatic data base: the all-time high for this date is 103 degrees F at Beardsley (Big Stone County) in 1922 and at Pipestone (Pipestone County) in 1925; the all-time low is 25 degrees F at Roseau (Roseau County) in 1918 and at Tower (St Louis County) in 1974.

Words of the Week: English Rule and American Rule of Groundwater Rights

Historically, under the common law doctrine, rights to utilize groundwater resources have been granted to landowners in the United States and many European countries. In humid climates with abundant precipitation and adequate recharge, the English Rule has applied which grants landowners absolute rights to pump as much water as they wish. This rule does not recognize the fact the pumping water from beneath one property will deplete acquifers that are shared with other property owners. In climates with deficit precipitation, inadequate recharge, and multiple users of groundwater resources, the American Rule applies, which allows landowners a so-called "reasonable use" taking into account the impacts on the water rights of others and depletion limits for specific acquifers. There are still many inconsistencies among states in groundwater rights, but the number of locations and situations where the English Rule applies is continuing to decline as a result of pressures to protect and conserve groundwater resources.

Outlook:

A somewhat quiet period of weather is in store for Minnesota. Temperatures will remain above normal with a notable absence of active weather fronts. Slight chance of showers in far northern counties on Saturday and Sunday, then in the south on Labor Day. Highs will be mostly in the 70s and 80s and lows in the 50s and 60s. To: Perry Finelli, Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Sept 11, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Did the ancient Egyptians harness wind power?

There is an intriguing article in the current issue of Weatherwise magazine which puts forth the theory that the ancient Egyptians may have used wind power to assist in the construction of pyramids, temples and obelisks. Maureen Clemmons, a California kite enthusiast has been experimenting with the use of kite-harnessed wind power to assist in erecting heavy objects like stone obelisks. Using large kites, called parafoils and deltawings, she has been able to raise 400 lb stones from a prone to an erect position in 15 to 25 mph winds. Another kite enthusiast, Bruce Flora of Orlando, FL was able to lift and move a Volkswagen Bus using a 14.5 ft by 12 ft kite.

The theory that the Egyptians may have used kite-harnessed winds to help in their construction projects meets with sketicism by many scientists. But Clemmons sites evidence that Egyptians were familiar with the power of the winds. They made large triangular shaped sails (called lateens) to power their barges on the Nile. In addition, many of their hieroglyphic paintings feature large wings, which Clemmons thinks may have represented kite designs. Lastly, climatologists describe the environment of ancient Egypt as a wetter and stormier one than that of today, with perhaps a higher frequency of strong winds.

Meanwhile, Clemmons hopes to get a research grant to further study her theories.

Topic: Anniversary of Hurricane Effects in Minnesota

This past Monday marked the 98th anniversary of the most lethal hurricane disaster in U.S. history. Galveston, TX was hit by 120 mph winds and a 20 foot storm surge on September 8, 1900. More than 6,000 people drowned and over 3600 homes were destroyed. This hurricane tracked north over Texas and the southern plains to merge with a cold front over Iowa by September 10th. The storm then produced a period of very heavy rains over Minnesota. In fact, the record Twin Cities rainfall for today's date of 3.11 inches is a direct result of this storm. Other parts of southern Minnesota reported 4 to 6 inches of rainfall as a result of this storm.

On Wednesday of this week, tropical storm Frances was bringing heavy rains to the Texas and Louisiana coasts. This is the third named tropical system in the Gulf of Mexico in recent weeks, following tropical storm Charley which inundated Del Rio, TX and hurricane Earl which brought heavy rains as it tracked over the southeastern states. None of these storms had direct impact on Minnesota, but if tropical storm activity continues this fall in the Gulf of Mexico, one of these systems may eventually migrate north and have some effect on our weather.

Twin Cities Almanac for Sept 11th:

The average MSP high temperature for this date is 73 degrees F (plus or minus 10 degrees standard deviation), while the average low is 53 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for Sept 11th:

MSP weather records for this date include: highest daily maximum temperature of 96 degrees F in 1895 and 1931; lowest daily maximum temperature of 51 degrees F in 1924; lowest daily minimum temperature of 35 degrees F in 1962; highest daily minimum temperature of 75 degrees F in 1931; record rainfall of 3.11 inches in 1900.

Average dew point for Sept 11th is 52 degrees F, with a maximum of 72 degrees F and a minimum of 25 degrees F.

All-time state records for Sept 11th:

Scanning the state climatic data base: the all-time high for this date is 111 degrees F at Beardsley (Big Stone County) in 1931 (this is also the all-time highest temperature for the month of September!); the all-time low is 22 degrees F at Ada (Norman County) in 1955.

Word of the Week: Khamsin

This is the Arabic name given to a class of winds which occur in Egypt and over the Red Sea. The word also means 50 and implies that the frequency of these winds is greatest during the 50 days following the Shem el Nassim holiday in April. But, most commonly these winds occur anywhere from February through June. These hot, dry winds are generally from the southeast, south, or southwest and may range from 30 to 40 mph, carrying a good deal of dust and sand. They result from low pressure systems moving along the Mediterranean near the coast of Egypt.

Historians and Egyptologists have associated these winds with the drifting sands that have buried many Egyptian structures and artifacts. They have also linked these winds to the highly eroded and weathered surfaces of Egyptian monuments, obelisks, and pyramids. Some have claimed that these winds may have assisted in the Exodus of the Israelites from Egypt across the Red Sea, by blowing strong enough to push back the waters.

Outlook:

Temperatures will average above normal over the weekend and most of next week in Minnesota. There will be a chance for showers beginning on Sunday and running through much of next week, as a series of low pressure systems pass to the north.

To: Perry Finelli, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Sept 18, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: New sources of weather information for travelers

For a number of years, motorists traveling the nation's highways have seen signpostings for radio frequencies which broadcast local weather updates. Along with NOAA weather radio, these radio broadcasts provide important sources of information so that travelers can anticipate changing or hazardous weather conitions along their route.

Two relatively new sources of weather information for travelers have been deployed in some states and both involve the use of cabletelevision's Weather Channel. In some highway rest stops, a kiosk or traveler information center will sometimes exhibit a television set that is tuned to the Weather Channel, especially when there are weather watches or warnings posted by the National Weather Service. In addition, some gasoline stations and truck stops have been experimenting with new fuel pumps which have built-in television sets. These sets broadcast the Weather Channel, allowing customers to view current conditions and forecasts while they fill up. There is a report in Weatherwise magazine about a station in Hutchinson, KS which offers this service and despite a somewhat higher price for gasoline has found customer feedback to be most positive.

MPR listener question: Hasn't the first half of September been one of the driest and warmest ever?

Answer: It depends on which part of the state you examine. For example, earlier this past week Duluth recorded nearly 2.5 inches of rainfall. However, other parts of the state have been bone dry. The Twin Cities, Rochester, and International Falls all recorded only a trace of rainfall for the first 15 days of the month. For Rochester and International Falls this represents the driest first half of September in this century. For the Twin Cities there have been two other Septembers when only a trace amount of rainfall was recorded in the first 15 days and those occurred in 1893 and 1996. This dry pattern is prevalent across the northern states all the way out to the Pacific northwest, where Eugene, OR has recorded over 80 consecutive days without rain, a new record for them.

As to the September warmth, the average high and low temperature in the Twin Cities for the first 15 days of the month have been 82 degrees F and 57 degrees F, respectively. This ranks as the 8th warmest first half of September in the historical record back to 1891.

The dryness and warmth have combined to dehydrate the landscape, accelerating the maturation and field drying of major crops as well as the leaf color change in deciduous trees.

Twin Cities Almanac for Sept 18th:

The average MSP high temperature for this date is 72 degrees F (plus or minus 10 degrees standard deviation), while the average low is 52 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for Sept 18th:

MSP weather records for this date include: highest daily maximum temperature of 93 degrees F in 1891; lowest daily maximum temperature of 47 degrees F in 1991; lowest daily minimum temperature of 32 degrees F in 1929; highest daily minimum temperature of 71 degrees F in 1955; record rainfall of 3.75 inches in 1905 and a trace of snowfall in 1863.

Average dew point for Sept 18th is 52 degrees F, with a maximum of 73 degrees F and a minimum of 32 degrees F.

All-time state records for Sept 18th:

Scanning the state climatic data base: the all-time high for this date is 100 degrees F at Montevideo (Chippewa County) in 1891; the all-time low is 14 degrees F at Angus (Polk County) in 1929.

Word of the Week: Dustbusting

This word may have several meanings, but for agricultural researchers it refers specifically to management techniques designed to mitigate wind erosion, especially of the type that produces dust and sandstorms. In many semiarid regions where overgrazing has occurred or where farmers have chosen to fallow agricutlural fields, wind erosion can lead to environmental degradation and produce a health and safety hazard. Loss of productive topsoil and decreased visibility on local roads and highways are two of the more obvious negative effects. In addition, recent research has revealed that in some areas small particulate air pollution may come predominately from airborne soil. The EPA is concerned about this, since particulates with diameters of 10 microns or less are small enough to penetrate the lungs.

Dustbusting techniques that have been tried and proven in such areas as the desert regions of California, include construction of barriers such as fences, planting of living windbreaks such as shrubs and trees, or revegetation of the landscape using native or adaptive plant species seeded from aircraft. In California, plants such as buckwheat, saltbushes, Indian ricegrass, and even Califonia poppy have served to revegetate barren landscapes.

Outlook:

A cooler and wetter pattern will try to settle in over the weekend. Skies should be cloudier than of late with temperatures cooler than normal. Some overnight lows in the 30s may occur in the north. There will be a chance for scattered shower activity late Saturday through Monday, especially up north. Another chance for rainfall by Thursday and Friday of next week.

The new seasonal outlooks released by the Climate Prediction Center favor a cooler than normal fall season for the western Great Lakes region, including Minnesota. To: Perry Finelli, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Sept 25, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Is October Your Favorite Month Too?

I came across this commentary about October's weather in an October, 1895 edition of the Minneapolis Journal....

"October is generally a kingly month in Minnesota. It opens with the usual affluence of sunshine and quickening, bracing air, which stimulates like the ichor of the Olympian gods. Day after day, the transformation of summer greenery into the royal and gorgeous tones of autumn will go on and summer's silent fingering will be overwoven with pageantry of color which no human art can call into being. The recessional of the year is grander than the processional...."

From numerous conversations with friends, I have drawn the conclusion that many Minnesotans cherish October as their favorite month of the year. Some of their October memories and connotations include.. A pageantry of landscape color...harvest festivals and dinners... visits to the applehouse and glasses of fresh cider..picking out pumpkins...song-filled hayrides...filling the pantry with the garden harvest...homemade pickles...frosty mornings with clear, blue skies...handmade sweaters and embroidered sweatshirts.. the bonfire rally...the last boat trip...migrating formations of birds...drying the last of the cut flowers...outdoor football on a comfortable Saturday afternoon...and many, many more.

Of course this affection for the month of October may be conditioned by the juxtaposition of arguably one of the worst months of the year, November, which has some rather negative connotations.... freezing rain..frozen ground and icing lakes..howling winds and first windchills...low, grey decks of clouds...blowing leaves... short days getting shorter..gloves, parkas and hats..seasonal affected disorder...onset of flu season...atmospheric inversions and morning fog...all-day rains...and other depressing thoughts. I always salvage the month by enjoying Thanksgiving!

MPR listener question from Carleton College: I've lived in a few places. But I've never lived in one like this as far as winds go. Here, quite regularly, as a rain storm approaches we'll have strong winds from, of all directions, the east. (This is not true for the summer thunderstorms though.) The clouds are always low, gray, and wet, and the rain always comes when it's like this. It happens very regularly. How is this? What of the prevailing westerlies carrying in the storms? I've lived in Ohio, Maryland, and seen lots of weather in many other locations. But I've never seen this regular east wind effect bringing the rain storms. Anything that might be said about this?

Answer: Geography is the key to this question. Located on the western side of the Great Lakes, we are subjected to east winds when large scale low pressure systems pass to the south of us. The larger, slow moving ones are capable of picking up moisture over the Great Lakes and delivering it to us here in Minnesota. The air temperature is also modified, making the rains generally cooler and the cloud ceiling lower (because of a lower condensation level in the atmosphere) and more stratified. This type of rain storm in the New England states is called a nor'easter because the winds pick up moisture over the Atlantic Ocean.

MPR listener question from Mankato: Which month has the highest relative humidity? It was awfully uncomfortable in July. Is that the month of highest humidity?

Answer: The comfort we feel as human beings is more related to the dewpoint than to relative humidity. The discomfort you felt in July was a result of dewpoints in the 60s and 70s which make it hard for our bodies to dissipate heat and evaporate sweat.

The rest of the answer is that relative humidity is nearly always in the 80 to 90 percent range overnight, regardless of what month it is. Perhaps the best comparison is to examine average daytime relative humidity values, when the air is more mixed by wind and convection from the land surface. These tend to be highest during the winter season, most commonly November through February when they range from 60 to 70 percent. Cooler winter temperatures mean the air can hold less moisture, but frequent inversions and lower cloud ceilings keep the moisture laden air close to the surface.

Twin Cities Almanac for Sept 25th:

The average MSP high temperature for this date is 67 degrees F (plus or minus 10 degrees standard deviation), while the average low is 46 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for Sept 25th:

MSP weather records for this date include: highest daily maximum temperature of 91 degrees F in 1920; lowest daily maximum temperature of 44 degrees F in 1926; lowest daily minimum temperature of 31 degrees F in 1926; highest daily minimum temperature of 68 degrees F in 1908; record rainfall of 1.34 inches in 1938.

Average dew point for Sept 25th is 45 degrees F, with a maximum of 68 degrees F and a minimum of 22 degrees F.

All-time state records for Sept 25th:

Scanning the state climatic data base: the all-time high for this date is 94 degrees F at Milan (Chippewa County) in 1897 and at Argyle (Marshall County) in 1938; the all-time low is 12 degrees F at Pokegama Falls (Itasca County) in 1894.

Words of the Week: Michael-riggs

This is an old term relating to Michaelmas, an English name for the fall season. Celebrated for St Michael, the patron saint of healing, Michaelmas Day falls on September 29 and is commonly marked by a harvest festival in many towns. Symbols of the festival include a glove, representing openhanded generosity, a cooked goose as the centerpiece of the harvest dinner, and gingerbread or gingerbeer because ginger is recognized as a healing spice.

Michael-riggs is the term given to the occasional strong gales which blow over England during this season. Rig by itself is an old English term for a gale, derived from the observation of how quickly a strong wind can fill the sailing rigs of ships.

Outlook:

A cold front will bring a chance of showers to the state on Saturday and perhaps into early Sunday. Temperatures will cool sharply behind the cold front, making Monday mornings lows dip into the 30s and 40s. The forecast models disagree for the balance of next week, presenting a highly uncertain situation for both temperatures and precipitation. Should Hurricane Georges enter the Gulf of Mexico over the weekend, we may see cooler Canadian air dominate us for most of next week. Precipitation chances will be on the rise for Wednesday through Friday.

To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Oct 2, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Preliminary Minnesota Climate Summary for September

September of 1998 was indeed a very dry month. Over 90 percent of the Minnesota weather observers report below normal rainfall. Many reported less than 30 percent of the long term average. The southern half of the state was relatively drier than the north. Temperatures statewide averaged several degrees F above the long term average for September. In fact for many communities this has been one of the warmest Septembers this century, ranking in the top 3 or 4.

September was kind to Minnesota farmers, providing abundant field working days such that the crop was harvested almost without interruption. Yields have been remarkably high in many areas and drying costs have been reduced because of favorable field drying conditions.

Topic: Still too early for fall nitrogen application

With the rapid progress in harvesting crops around the state, many farmers are anxious to do fall tillage and apply ammonium- nitrogen fertilizer for next year's crop. However, recent soil temperatures indicate it is still to early for nitrogen applications. Soil temperatures at the 4 inch depth are averaging from 58 to 66 degrees F. This will promote rapid conversion of ammonium-nitrogen to nitrate-nitrogen, a form that is subject to denitrification and leaching loss, which may proceed at such a rate as to leave little in the soil for next spring. For an economic and efficient fall nitrogen application, patience is in order until soil temperatures fall below the 50 degree F level. At temperatures below this threshold the conversion of ammonium- nitrogen to nitrate-nitrogen occurs at a much slower rate, insuring that most will be conserved for next spring's crop.

MPR listener question: This September has to be one of the warmest in recent memory. How many days of 90 degrees F or higher were recorded and was that a record number?

Answer: Indeed, September was one of the warmest statewide this century. The Twin Cities recorded 4 days with maximum temperatures of 90 degrees F or above. The long term average (1891-1997) is just one day. The record number of days with temperatures of 90 degrees F or greater during September is eight days way back in 1895. I think it seemed so unusual because we had a total of only 3 such days in all of the other months this year.

Incidentally, both Fargo, ND and La Crosse, WI recorded five days in September with temperatures of 90 degrees F or greater. This too was not a record, but Fargo's high temperature of 97 degrees F on September 10th was their hottest day of the year!

Twin Cities Almanac for October 2nd:

The average MSP high temperature for this date is 67 degrees F (plus or minus 10 degrees standard deviation), while the average low is 46 degrees F (plus or minus 7 degrees standard deviation).

MSP Local Records for October 2nd:

MSP weather records for this date include: highest daily maximum temperature of 89 degrees F in 1953; lowest daily maximum temperature of 44 degrees F in 1944; lowest daily minimum temperature of 22 degrees F in 1974; highest daily minimum temperature of 62 degrees F in 1897; record rainfall of 0.85 inches in 1900.

Average dew point for October 2nd is 42 degrees F, with a maximum of 68 degrees F and a minimum of 18 degrees F.

All-time state records for October 2nd:

Scanning the state climatic data base: the all-time high for this date is 95 degrees F at Wheaton (Traverse County) in 1953; the all-time low is 9 degrees F at Karlstad (Kittson County) in 1974.

Words of the Week: Heat-burst

Like a downburst from a thunderstorm which brings destructive winds, a heat-burst sometimes occurs as a result of sinking motion within the downdrafts of thunderstorms. It is not destructive, but it does bring a rise in temperature as a result of compressional heating (rising air cools, falling air warms). This can produce some remarkable effects as it did last Friday at Sioux City, IA. At 10pm, well after sunset, a heat burst occurred which temporarily raised the surface temperature from 84 degrees F to 93 degrees F, a value which tied the all-time record high for that date (Sept 25th). As the thunderstorm cell passed by, the temperature dropped to 82 degrees F in less than one hour.

Outlook:

A cooling trend with chances for widely scattered showers in southern Minnesota on Saturday, spreading into northern counties by Sunday. Temperatures will be near normal or a bit cooler than normal through the first week of October and there will be good chances for precipitation through mid week, especially on Wednesday.

To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Oct 9, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Anniversary of the Great Fires of 1871

The Great Lakes States suffered perhaps their worst ever fire season in the fall of 1871. The summer had been a very dry one, although this does not show up in the long-term Twin Cities record. The U.S. Army Signal Corps had only initiated a network of precipitation observations across the region beginning in 1870 and reports were very sparse. The Pioneer Press reported on the very low stage of the Mississippi River, the St Croix River, and the Red River of the North. The Mississippi River running through the Twin Cities was reportedly at its lowest stage in seven years. This suggests that the surrounding landscape was indeed very dry. Farm reports spoke of parched fields and large cracks in the soil.

Fires began in western Minnesota, from Breckenridge south to the Iowa border during the month of September. By October, the Pioneer Press was reporting smoky air, clouds of dust, fires lighting up the western horizon, obscured sunlight, and cinders in the air. The prairie fires peaked on October 8th in a very destructive manner. Fires destroyed farm fields, buildings and homes in the New Ulm area. Elsewhere at the same time, even greater destruction occurred: a fire broke out near Peshtigo, WI destroying the town in less than one hour and claiming 1200 lives in Door and Kewaunee Counties while scorching 1.2 million acres; the Great Chicago Fire began on the evening of the 8th of October in a stable behind the O'Leary home and was not completely extinguished until October 10th by which time it had destroyed over 17,000 buildings and killed over 200 people*; numerous fires also broke out in Michigan and burned over 2 million acres, mostly forested lands, killing 200 people. Snow and rain during the remainder of October helped to bring an end to this terrible fire season.

Interesting narratives about these fires can be found on the Internet at... http://www.crh.noaa.gov/grb/PeshtigoFire.html (Green Bay, WI Weather Service Office) http://taiga.geog.niu.edu/nwslot/fire.html (Chicago, IL Weather Service Office)

*Footnote: the Chicago weather office of the Army Signal Corps was destroyed in this fire, along with all the early climatological data records. They had reportedly only recorded 1 inch of rainfall from July to October.

MPR listener question: How long ago did the National Weather Service begin its hurricane forecasting service?

Answer: The National Weather Service initiated a 24 hour hurricane forecast and warning service in 1935. Actually, the organization made an initial serious attempt to forecast hurricanes during the Spanish-American War in 1898. This effort was intended to support the U.S. Naval forces operating in the Caribbean Sea and Gulf of Mexico. I don't know how successful this initial effort was.

MPR listener question: Yesterday (October 8th) produced the first official frost (32 degrees F or colder) in the Twin Cities area, according to the National Weather Service, when the MSP Airport reported a low of 32 degrees F between 7 am and 8 am. Wasn't this very close to the historical average and what have been the earliest and latest first fall frosts in the Twin Cities?

Answer: Yes, yesterday's reading of 32 degrees F at the MSP airport was very close to the date of the long term average for first fall frost in the Twin Cities, which is October 10th. The earliest ever was September 3, 1974 and the latest ever was November 7, 1900.

Twin Cities Almanac for October 9th:

The average MSP high temperature for this date is 60 degrees F (plus or minus 10 degrees standard deviation), while the average low is 41 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for October 9th:

MSP weather records for this date include: highest daily maximum temperature of 86 degrees F in 1938; lowest daily maximum temperature of 38 degrees F in 1906, 1925, and 1985; lowest daily minimum temperature of 22 degrees F in 1895; highest daily minimum temperature of 64 degrees F in 1973; record rainfall of 1.82 inches in 1904.

Average dew point for October 9th is 40 degrees F, with a maximum of 68 degrees F and a minimum of 20 degrees F.

All-time state records for October 9th:

Scanning the state climatic data base: the all-time high for this date is 91 degrees F at Montevideo (Chippewa County) in 1980; the all-time low is 5 degrees F at Mizpah (Koochiching County) in 1932.

Word of the Week: Haugull

This is not a type of seabird, but a Scottish term used to describe a cold, damp wind blowing from the sea. This type of wind often brings either fog, rain or mist. The literal meaning of this word is a "gray coastal meadow." The term is also used in Norway. It could apply equally to the type of weather experienced in Duluth and along the northshore earlier this week (especially Monday), when a cool east wind brought fog, rain and mist inland over the hills and meadows of the Superior National Forest.

Outlook:

Increasing clouds late Saturday, with a chance for showers continuing right through Monday. Both Sunday and Monday look to be windy days. Temperatures will be cooler than normal for much of next week, with another chance for showers by Thursday. To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Oct 16, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

MPR listener question: With a La Nina episode in place in the equatorial Pacific Ocean, should we brace ourselves for a costly heating season here in Minnesota? How come we are not reading about weather catastrophes associated with La Nina?

Answer: We have documented fewer episodes of La Nina (the cold phase in the equatorial Pacific Ocean) than El Nino, so the body of evidence as to climatic effects is much less. Secondly, the correlations of La Nina episodes with unusual climate patterns are far fewer and less significant than those for El Nino. Most catatrosphic weather events are not associated with El Nino or La Nina, though sometimes through media coverage it may seem that way. Concerning your winter heating bill, history suggests that we have a higher probability for colder than normal temperature conditions this winter as a result of the moderate La Nina which is presently in place. However, this just increases the probability of such conditions and does not guarantee them.

Topic: New monthly and seasonal climate outlook for Minnesota

The new monthly and seasonal climate outlooks from the Climate Prediction Center favor colder and wetter than normal conditions for much of the western Great Lakes, including most of Minnesota. This pattern is expected to develop in November and persist through January. Thus we may see some early snows this fall around the state, but in many agricultural areas additional moisture to recharge the soils would be welcome.

Twin Cities Almanac for October 16th:

The average MSP high temperature for this date is 61 degrees F (plus or minus 12 degrees standard deviation), while the average low is 41 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for October 16th:

MSP weather records for this date include: highest daily maximum temperature of 86 degrees F in 1938; lowest daily maximum temperature of 32 degrees F in 1952; lowest daily minimum temperature of 23 degrees F in 1952; highest daily minimum temperature of 60 degrees F in 1947; record rainfall of 2.10 inches in 1984 and record snowfall of 0.5 inches in 1992.

Average dew point for October 16th is 38 degrees F, with a maximum of 63 degrees F and a minimum of 9 degrees F.

All-time state records for October 16th:

Scanning the state climatic data base: the all-time high for this date is 88 degrees F at St Peter and New Ulm in 1938 and at Pipestone in 1958; the all-time low is 4 degrees F at Bemidji Beltrami County) in 1952.

Word of the Week: Chocolatero (the chocolate gale)

This is the term used to describe a moderate to strong northern wind in the Gulf region of Mexico. Such a wind ushers in cold high pressure from the continental United States and temperatures drop markedly. These winds are most common between November and April. The origin of this term is unclear, but I suspect that it has something to do with drinking hot chocolate!

Outlook:

Looks to be a rainy, windy weekend most places around the state with falling temperatures. Some showers may linger into Sunday night. There is a chance of snow flurries Sunday in the far north. Temperatures will average colder than normal for much of next week, but Monday through Wednesday looks to be drier. To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Oct 23, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Icebergs

According to the National Ice Center, an iceberg that was 92 miles long and 30 miles wide, or approximately one and a half times the size of Delaware had broken off the Antarctica ice sheet late last week. After breaking off the Ronne Ice Shelf, it was drifting in the Weddell Sea, where it was surrounded by sea ice. The discovery was made from the analysis of satellite images obtained from a polar orbiting meteorological satellite.

This is one of the largest icebergs ever tracked by the National Ice Center. If we make some assumptions about its thickness (estimate 0.05 miles) and density (0.9 for ice) we can calculate its water equivalence. This works out to be about 150 trillion gallons of water. It is estimated that the Twin Cities metro area consumes about 400 millions gallons of water each day, so this iceberg may contain enough water to meet our present needs for over 1000 years. That's a great deal of water.

As the southern hemisphere approaches the summer season, the National Ice Center carefully monitors and tracks larger icebergs for shipping navigation in the Antarctic region. Their web site is.... http://www.natice.noaa.gov/index.htm

MPR listener question: How often do we break a daily climate record in Minnesota? It seems to be fairly frequent.

Answer: It depends on how we look at it. Statewide, across all the communities that monitor climate, we probably record hundreds of new record daily temperatures and precipitation each year. For an single community in the state it is much less frequent. For example, in the Twin Cities we record new record daily temperatures (maximum or minimum) and new record daily precipitation (rainfall or snowfall) an average of 8 to 12 times each year. This frequency suggests that during a lifetime as a resident of Minnesota, you are probably witness to 500 to over 1000 record setting weather events! This year has been relatively quiet in terms of setting daily climate records in the Twin Cities. I think we have recorded only 6 so far.

Twin Cities Almanac for October 23rd:

The average MSP high temperature for this date is 55 degrees F (plus or minus 11 degrees standard deviation), while the average low is 37 degrees F (plus or minus 8 degrees standard deviation).

MSP Local Records for October 23rd:

MSP weather records for this date include: highest daily maximum temperature of 82 degrees F in 1899; lowest daily maximum temperature of 34 degrees F in 1981; lowest daily minimum temperature of 17 degrees F in 1936; highest daily minimum temperature of 55 degrees F in 1970; record rainfall of 1.01 inches in 1995 and record snowfall of 1.4 inches in 1938. There have been three measurable snowfalls on this date since 1938.

Average dew point for October 23rd is 36 degrees F, with a maximum of 65 degrees F and a minimum of 9 degrees F.

All-time state records for October 23rd:

Scanning the state climatic data base: the all-time high for this date is 91 degrees F at Chatfield (Fillmore County) in 1927; the all-time low is -10 degrees F at Grand Rapids (Itasca County) in 1917 (this occurred with 5 inches of snow cover).

Word of the Week: Freezing level

This is a term used in meteorology to refer to the lowest altitude in the atmosphere over a given location at which the air temperature is 32 degrees F (0 degrees C). In other words, the height of the 32 degree temperature surface. It is highly variable and changes markedly with the seasons in Minnesota. In summer it might be as high as 10,000 ft, while in winter it comes right down to the ground at times. Average height of the freezing level at MSP airport during the first week of November is about 3200 ft, but by the end of the month it is about 1200 ft. This change in average freezing level during the month of November is associated with a number of other significant changes in climate during the month including: over a 1 hour reduction in daylength (over 10 hrs to just over 9 hrs); an 18 degree decline in daily mean temperature (from 40 degrees to 22 degrees); an increase in cloudiness; and a increase in the occurrence of freezing precipitation (freezing rain, sleet, snow).

Outlook:

Looks to be a few degrees warmer than normal over the weekend and for most of next week. A chance for showers statewide on Sunday, and continuing Monday and Tuesday up north. Another chance for showers statewide by Halloween, followed by a drop in temperatures. To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Oct 30, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Changes in NOAA Weather Radio

The recent modernization of the National Weather Service includes provisions to expand and upgrade NOAA Weather Radio (NWR) services. For many residents this is the most timely and best source of relevant weather information. Improvements in NWR will be phased in over the next 6 to 12 months. Some of the expected changes in NWR include...

Use of synthesized voice technology to broadcast watches, warnings, current conditions, nowcasts, and climatological summaries in a more timely manner.

More timely transmission through a new Console Replacement System, which will allow simultaneous release of text products to wire services and the Internet, as well as synthesized voice broadcasts all from a single keystroke. This should especially improve the timeliness in the delivery of weather warnings and current weather conditions.

New Specific Area Message Encoders (SAME) are deployed in the latest weather radios. These allow listeners to pre-select alarms and broadcasts that only relate to their county.

Up to 13 transmitters can be controlled from a single forecast office and taylored to meet the needs of specific counties. Efforts are underway to expand the number of transmitters in Minnesota in order to provide great areal coverage of relevant weather information.

More on NOAA Weather Radio is available at the forecast office web site.....http://www.crh.noaa.gov/mpx/radio1.html

I must admit, though I welcome these changes in the NWR system, I will miss the personalities of the National Weather Service employees I have learned to recognize through their radio voices.

MPR listener question: How many heavy snows do we typically have in the month of November and when do we usually get permanent winter snowcover?

Answer: This depends on what we mean by heavy snow. In the past 50 years, the Twin Cities records show 36 daily snowfalls of 3 inches or greater during November and only 11 daily snowfalls of 6 inches or greater. These numbers are 10 to 20 percent higher for some northeastern Minnesota communities, along the Superior highlands. As to the question of establishing permanent snow cover, snow climatology shows that the average date for first 1 inch snow cover varies from October 30th at Crane Lake in northern St Louis County to December 1st at Albert Lea along the Iowa border. The average date of first 1 inch snowcover in the Twin Cities is November 22nd. Incidentally, the forecast appears to favor some snow around the state in early November.

Twin Cities Almanac for October 30th:

The average MSP high temperature for this date is 53 degrees F (plus or minus 13 degrees standard deviation), while the average low is 35 degrees F (plus or minus 9 degrees standard deviation).

MSP Local Records for October 30th:

MSP weather records for this date include: highest daily maximum temperature of 83 degrees F in 1950; lowest daily maximum temperature of 30 degrees F in 1913, 1917, and 1925; lowest daily minimum temperature of 10 degrees F in 1925; highest daily minimum temperature of 57 degrees F in 1933; record rainfall of 1.26 inches in 1971 and record snowfall of 0.8 inches in 1951. Maximum snow depth on this date is 1 inch in 1955 and there have been three measurable snowfalls since 1948.

Average dew point for October 30th is 35 degrees F, with a maximum of 63 degrees F and a minimum of 6 degrees F.

All-time state records for October 30th:

Scanning the state climatic data base: the all-time high for this date is 90 degrees F at Canby (Yellow Medicine Coutny) in 1950; the all-time low is -2 degrees F at Tower (St Louis County) in 1988.

Word of the Week: Smaze

Not used much anymore, this used to be a more common term used in describing a weather condition that was a combination of smoke and haze, or a very light smoke condition that resembled haze. It was more typically used in the 1930s, 1940s, and 1950s in the industrial cities of the United States to describe conditions that were quite frequent during the winter months when inversions can keep haze and smoke around for many consecutive days. However, I don't think it counts in a game of Scrabble!

Outlook:

As opposed to most of September and October, it looks as though the first full week of November will be colder than normal, It appears that the early part of the week may be cool and dry, with increasing clouds and chances for precipitation by the middle and end of next week. Temperatures may be cool enough for some snow showers in the north and central counties by the end of the week. To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Nov 13, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: The November 10, 1998 storm - a record setter

Tuesday of this week brought a record setting storm across the region, with blizzard conditions in of southern and western Minnesota. Duluth reported a record precipitation for the date of 2.33 inches, and record snowfall of 7.2 inches. Two Harbors and Cloquet also reported record setting amounts of precipitation exceeding 2 inches. The following locations reported record snowfall amounts for November 10th... Madison 10 in. Montevideo 8 in Granite Falls 7 in. Alexandria 6 in. Little Fork 7.1 in. International Falls 5.4 in.

But perhaps the most astonishing feature of this storm was the record setting low barometric pressure. This is a measure of the storms intensity and relates closely to the strength of the wind speeds measured around the state, many of which exceeded 60 mph. MSP Airport (28.55 in.), Rochester (28.47 in.) and Duluth (28.47 in.) all reported the lowest barometric pressure ever measured at those locations. Barometric readings at Albert Lea and Austin registered 28.43 inches which is the lowest pressure value ever measured anywhere in the state. To put these measurements in context, these values are lower than the central pressure measured in 9 of the 13 named tropical storms and hurricanes in the Atlantic this year.

MPR listener question: I heard you talking about famous November storms on the Midday program this week. There were many of them to talk about. But which date in November has the highest probability for a snow storm?

Answer: This is an interesting question. I would have guessed that there might not be much difference in probability from day to day, but after checking the MSP historical records I find there is quite a difference. The dates with the highest probability for measurable snowfall are November 23 and 26, both showing close to a 40 percent occurrence. This confirms the perception that we often have snow around Thanksgiving in Minnesota, dating back to the famous Thanksgiving blizzard in central and northern counties on November 26, 1896.

The November date with the lowest probability for snowfall is the 7th with just a 5 percent occurrence, while today's date, the 13th has about a 1 in 4 chance (25 percent) for snowfall.

A final note on November storms. The very first winter storm warning issued in the United States by the U.S. Army Signal Corps Weather Service came on November 8, 1870.

Topic: Ralph Abercromby - meteorologist and photographer

During the 1870s there was increasing use of photography in scientific investigations. In meteorology, one of the pressing needs was to photograph cloud forms and publish a cloud atlas which would illustrate the cloud classification system proposed by Luke Howard in the early 1800s and serve as a reference to meteorological organizations making daily weather observations which included sky cover, cloud types and estimated cloud heights. Up until that time, drawings and sketches of cloud forms had served as observational guidelines for classifying cloud types.

To meet the need of the international meteorological community, English photographer Ralph Abercromby made a series of voyages around the world from 1884 to 1886 with the express purpose of taking as many pictures of different cloud forms as he could find. His camera was bulky and unwieldy, using large gelatin plates to capture the images. By 1887 his collection was large and diverse enough to publish the first cloud atlas using photographs.

Today, the modern International Cloud Atlas not only contains color photos of cloud types taken from observers on the ground, but also images taken from airplanes and orbiting satellites

Twin Cities Almanac for November 13th:

The average MSP high temperature for this date is 41 degrees F (plus or minus 11 degrees standard deviation), while the average low is 26 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for November 13th:

MSP weather records for this date include: highest daily maximum temperature of 68 degrees F in 1930; lowest daily maximum temperature of 15 degrees F in 1940; lowest daily minimum temperature of 0 degrees F in 1986; highest daily minimum temperature of 50 degrees F in 1944; record rainfall of 1.04 inches in 1951 and record snowfall of 4.0 inches in 1997. There have been eleven measurable snowfalls on this date since 1948. Maximum snow depth has been 11 inches in 1991 and the worst windchill conditions were -31 degrees F readings in the early morning of 1986.

Average dew point for November 13th is 26 degrees F, with a maximum of 49 degrees F and a minimum of -7 degrees F.

All-time state records for November 13th:

Scanning the state climatic data base: the all-time high for this date is 72 degrees F at Beardsley (Big Stone County) in 1939 and at St Peter (Nicollet County) in 1944; the all-time low is -24 degrees F at Tower (St Louis County) in 1995.

Word of the Week: Spelaeo-meteorology

Derived partially from the Greek word for cave, spelaion, this term means the study of the atmosphere of caves. Research into the atmospheric properties of caves began to flourish in the 1950s and 1960s partially motivated by the medical community which sought to treat patients with bronchial or asthmatic diseases by using cave therapy. The air inside caves was thought to have qualities that would help alleviate respiratory problems. Measurements were made to confirm that the cave atmosphere was (1) more humid, (2) free of allergens such as pollens and dusts, (3) had a lower pH which would restrict the virulence of pathogenic germs, and (4) contained a higher concentration of carbon dioxide which would induce patients to breathe deeper.

With better controlled environments for patients now available in modern medical facilities, I don't think the medical profession is as interested in spelaeo-meteorology as they once were.

Outlook:

It will be a cloudy period with chances for rain in the southern counties and snow in the north Saturday through Monday, drier on Tuesday, then more chances for precipitation around the state Wednesday through Friday of next week as a major low pressure system approaches the state. Temperatures will moderate a few degrees above normal, with highs in the 30s and 40s and lows mostly in the 20s.

To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Nov 13, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: The November 10, 1998 storm - a record setter

The November date with the lowest probability for snowfall is the 7th with just a 5 percent occurrence, while today's date, the 13th has about a 1 in 4 chance (25 percent) for snowfall.

A final note on November storms. The very first winter storm warning issued in the United States by the U.S. Army Signal Corps Weather Service

file:///G|/1998/WeatherTalk_1998-11-13.txt[9/22/2015 3:52:09 PM] came on November 8, 1870.

Topic: Ralph Abercromby - meteorologist and photographer

Today, the modern International Cloud Atlas not only contains color photos of cloud types taken from observers on the ground, but also images taken from airplanes and orbiting satellites

Twin Cities Almanac for November 13th:

The average MSP high temperature for this date is 41 degrees F (plus or minus 11 degrees standard deviation), while the average low is 26 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for November 13th:

Average dew point for November 13th is 26 degrees F, with a maximum of 49 degrees F and a minimum of -7 degrees F.

All-time state records for November 13th:

Word of the Week: Spelaeo-meteorology

With better controlled environments for patients now available in modern medical facilities, I don't think the medical profession is as interested in spelaeo-meteorology as they once were.

Outlook:

file:///G|/1998/WeatherTalk_1998-11-13.txt[9/22/2015 3:52:09 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Nov 20, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: November 1896, The Coldest November

It looks like this November will end up being somewhat colder than normal, but not drastically so. Many Minnesotans remember the Halloween Blizzard of 1991, the record-setting snowfall in November, and the numerous mornings with below zero temperature readings. However, November of 1991 with a statewide average temperature of 22 degrees F, only ranked 11th among the state's coldest Novembers. The coldest was perhaps 1896 with a statewide average temperature of 16.7 degrees F. (This recognition is somewhat uncertain with repect to the older pioneer records which suggest that the Novembers of 1872 and 1875 may have been equivalent and that 1880 may have even been colder yet when the temperature in St Paul never rose above freezing from the 16th to the 30th.)

Some of the features of November 1896 documented in the records include....

Eleven mornings with below zero temperatures, culminating in a record setting November low of -45 degrees F at Pokegama on the 30th

A Thanksgiving Holiday blizzard in central and northern counties on the 25 and 26th which dropped up to a foot of snow, and produced -40 to -50 degree F windchill conditions.

Rivers frozen up extraordinarily early. The Red River at Fargo- Moorhead was covered with 14 inches of ice by the end of the month. The Mississippi River at St Paul was closed to navigation on the 21st and frozen solid a few days later, so that ice skaters and sleds were moving across it.

The low temperatures caused an ice gorge to form around a log boom a few miles upstream from Alma, WI. This ice gorge grew to a length of many miles and blocked the flow of the Mississippi out of Lake Pepin, flooding the surrounding lowlands near Wabasha. Ice was seen on the river as far south as Hannibal, MO.

Topic: New monthly and seasonal outlooks from the Climate Prediction Center

The new outlooks from the Climate Prediction Center favor a colder than normal December for Minnesota, especially in the western counties, which have already been getting snow cover. December also looks to be wetter than normal in the north, but somewhat near normal in southern Minnesota. The winter season outlook for December through February favors greater than normal precipitation for the northern half of the state and perhaps colder than normal conditions in the Red River Valley.

These outlooks are best on recent climate trends and past association with La Nina effects.

MPR listener question: Which month has the highest frequency of fog in the Twin Cities?

Answer: December shows the highest frequency of fog historically, followed by January and February. Winter inversions are common during these months keeping moist air trapped near the ground. Fog can more easily form at night under these conditions, and in December, there is nearly a 36 percent occurrence, meaning that typically on 11 days during the month fog is reported. By the way, the month with the lowest frequency of fog is July.

Twin Cities Almanac for November 20th:

The average MSP high temperature for this date is 40 degrees F (plus or minus 11 degrees standard deviation), while the average low is 25 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for November 20th:

MSP weather records for this date include: highest daily maximum temperature of 63 degrees F in 1925; lowest daily maximum temperature of 17 degrees F in 1937 and 1978; lowest daily minimum temperature of -3 degrees F in 1921; highest daily minimum temperature of 43 degrees F in 1930 and 1990; record precipitation of 2.01 inches in 1975 and record snowfall of 8.0 inches in 1975. There have been ten measurable snowfalls on this date since 1948. Maximum snow depth has been 10 inches in 1981 and the worst windchill conditions were -30 degrees F readings in the early morning of 1921 and 1985.

Average dew point for November 20th is 24 degrees F, with a maximum of 54 degrees F and a minimum of -1 degrees F.

All-time state records for November 20th:

Scanning the state climatic data base: the all-time high for this date is 74 degrees F at Faribault (Rice County), St Charles (Winona County), and Pleasant Mound (Blue Earth County) in 1897; the all-time low is -31 degrees F at Roseau (Roseau County) in 1896.

Words of the Week: Gorge

This term is used by many Americans to describe a Thanksgiving Holiday habit, but that is not the definition I intend. The term is used by hydrologists to describe a blockage in a stream or river. This may be in the form of ice, debris such as old logs, or a composite of both. A gorge can be particularly destructive during the onset of winter conditions by blocking the stream or river and allowing surroundings lowlands to flood, or the shoreline to be scoured away by moving ice or depris.

Outlook:

Warm, dry weekend coming up, perhaps the last one of the season for wrapping up outdoor chores. Temperatures will be above normal for the weekend and early next week. Chances for snow showers in the north by Monday, then a chance for mixed showers by Thanksgiving and the Friday after, with a cooling trend for the weekend.

To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Nov 20, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: November 1896, The Coldest November

Some of the features of November 1896 documented in the records include....

Eleven mornings with below zero temperatures, culminating in a record setting November low of -45 degrees F at Pokegama on the 30th

A Thanksgiving Holiday blizzard in central and northern counties on the 25 and 26th which dropped up to a foot of snow, and produced -40 to -50 degree F windchill conditions.

Topic: New monthly and seasonal outlooks from the Climate Prediction Center

The new outlooks from the Climate Prediction Center favor a colder than normal December for Minnesota, especially in the western counties, which have already been getting snow cover. December

file:///G|/1998/WeatherTalk_1998-11-20.txt[9/22/2015 3:52:09 PM] also looks to be wetter than normal in the north, but somewhat near normal in southern Minnesota. The winter season outlook for December through February favors greater than normal precipitation for the northern half of the state and perhaps colder than normal conditions in the Red River Valley.

These outlooks are best on recent climate trends and past association with La Nina effects.

MPR listener question: Which month has the highest frequency of fog in the Twin Cities?

Twin Cities Almanac for November 20th:

The average MSP high temperature for this date is 40 degrees F (plus or minus 11 degrees standard deviation), while the average low is 25 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for November 20th:

Average dew point for November 20th is 24 degrees F, with a maximum of 54 degrees F and a minimum of -1 degrees F.

All-time state records for November 20th:

Words of the Week: Gorge

This term is used by many Americans to describe a Thanksgiving Holiday habit, but that is not the definition I intend. The term is used by hydrologists to describe a blockage in a stream or file:///G|/1998/WeatherTalk_1998-11-20.txt[9/22/2015 3:52:09 PM] river. This may be in the form of ice, debris such as old logs, or a composite of both. A gorge can be particularly destructive during the onset of winter conditions by blocking the stream or river and allowing surroundings lowlands to flood, or the shoreline to be scoured away by moving ice or depris.

Outlook:

file:///G|/1998/WeatherTalk_1998-11-20.txt[9/22/2015 3:52:09 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Nov 27, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Thanksgiving Day, Fasting Day, and Climatology

Historically, Christian people have held Thanksgivings to celebrate and recognize the gifts and mercies of God. This has often taken the form of a harvest festival or a banquet in the fall. Conversely, Fasting Days were often scheduled as a recognition of God's harsh judgements, a way for reconciliation or atonement. These quite often occurred in the spring. But long ago neither of these events were typically observed on fixed calendar dates. Some would say that they were more related to climate.

When harvests were made bountiful by a blessed rain or abundant sunshine or when fish and game were caught in great numbers by hunters and fishermen, a community might declare a Thanksgiving Day to celebrate these gifts. Alternatively, if the winter was harsh, game was scarce, there was spring flooding, or drought related forest fires, then a community might declare a Fasting Day in an attempt to reconcile with God. Often times this was coincident with the depletion of winter stored food anyway, so there was little to eat. Thus many of these occasions were at least partially dictated by climate and weather variations as they affected agriculture, fish and game, or the hospitality of the local environment.

In early American history, Thanksgiving could be declared independently by a local community, church or colonial government. These were often celebrated on a weekday that was called "Lecture Day", typically a Wednesday or Thursday when a topical sermon was given each week. An annual autumn Thanksgiving was pretty well established in many American colonies by the middle of the 17th century and a feast or banquet built around harvested crops and game became customary. The Continental Congress and early Presidents like Washington and John Adams declared periodic Thanksgivings, often in the month of December. In 1815, President James Madison declared two national Thanksgivings. In 1863, President Lincoln declared a Thanksgiving for the last Thursday of November which became a national holiday of sorts until President Franklin Roosevelt signed a bill in 1941 official making Thanksgiving Day the fourth Thursday of each November. This date which varies from November 22nd to November 28th adheres to the tradition of following the agricultural harvest and hunting seasons, however it also coincides with a highly volatile climate transition from fall to winter. Thus this holiday in particular is perhaps loaded with more weather-related memories than any other American holiday.

MPR listener question: I played golf last Sunday and intend to play at least one more round over the Thanksgiving holiday (if the forecast is right!). I am somewhat of a newcomer to this state and have yet to experience winter. How often does Mother Nature favor a round of golf over the Thanksgiving holiday weekend in the Twin Cities?

Answer: This is a question I have never really considered because I suspect the answer is hardly ever. To answer it, I had to subjectively choose what I thought to be tolerable conditions for a round of golf: daytime temperature of at least 50 degrees F, no snow cover, at least partly sunny skies with no precipitation falling, and winds of less than 20 mph. Next, I examined the Twin Cities daily climate records for every four-day Thanksgiving weekend back to 1891.

I found exactly eight years with weather conditions that were suitable for golf (presuming that the courses were open to the public). They were 11/26/1899 (Sun), 11/22-11/23/1907 (Fri-Sat), 11/26/1914 (Thu), 11/27-11/28/1941 (Thu-Fri), 11/25-11/26/1960 (Fri-Sat), 11/25/1961 (Sat), 11/24-11/25/1984 (Sat-Sun), and 11/24/1990 (Sat). The warmest occasion was in 1914 when the temperature soared to a record-setting 62 degrees F. But, eight opportunities in 108 years is not too many. So if you can indeed play golf this Thanksgiving weekend in the Twin Cities, it may perhaps be a singular event in your lifetime! I wouldn't count on starting a tradition.

Twin Cities Almanac for November 27th:

The average MSP high temperature for this date is 32 degrees F (plus or minus 10 degrees standard deviation), while the average low is 18 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for November 27th:

MSP weather records for this date include: highest daily maximum temperature of 61 degrees F in 1909; lowest daily maximum temperature of 7 degrees F in 1897 and 1930; lowest daily minimum temperature of -6 degrees F in 1897; highest daily minimum temperature of 37 degrees F in 1913 and 1962; record precipitation of 0.90 inches in 1905 and record snowfall of 9.0 inches in 1905. There have been fifteen measurable snowfalls on this date since 1948. Maximum snow depth has been 15 inches in 1948 and the worst windchill conditions were -46 degrees F in the late morning of 1955.

Average dew point for November 27th is 17 degrees F, with a maximum of 38 degrees F and a minimum of -14 degrees F.

All-time state records for November 27th:

Scanning the state climatic data base: the all-time high for this date is 63 degrees F at Winona (Winona County) in 1909; the all-time low is -29 degrees F at Mahnomen (Mahnomen County) in 1985.

Words of the Week: Cold Soak

This is what some Minnesotans do after they emerge from several minutes in a hot sauna. It is also a term used by climatologists and engineers to describe equipment exposure in cold climates, especially in polar regions. Machinery or engines which are stored or left idle in cold climates experience a cold soak. Metal becomes more brittle, lubricants thicken and operational tolerances are diminished. Preheating of the machinery before use is often prescribed for equipment that has been cold soaked for extended periods.

Outlook:

Generally a nice Thanksgiving weekend is expected, with mild temperatures several degrees warmer than normal. Increasing clouds in the north later on Saturday with a chance for mixed precipitation. Chance for showers on Sunday statwide, lingering into Monday morning in eastern sections. Continued mild temperatures into next week, with a chance for rain and snow showers around the state by Wednesday. To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Nov 27, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Thanksgiving Day, Fasting Day, and Climatology

file:///G|/1998/WeatherTalk_1998-11-27.txt[9/22/2015 3:52:10 PM] climate transition from fall to winter. Thus this holiday in particular is perhaps loaded with more weather-related memories than any other American holiday.

Twin Cities Almanac for November 27th:

The average MSP high temperature for this date is 32 degrees F (plus or minus 10 degrees standard deviation), while the average low is 18 degrees F (plus or minus 10 degrees standard deviation).

MSP Local Records for November 27th:

Average dew point for November 27th is 17 degrees F, with a maximum of 38 degrees F and a minimum of -14 degrees F.

file:///G|/1998/WeatherTalk_1998-11-27.txt[9/22/2015 3:52:10 PM] All-time state records for November 27th:

Scanning the state climatic data base: the all-time high for this date is 63 degrees F at Winona (Winona County) in 1909; the all-time low is -29 degrees F at Mahnomen (Mahnomen County) in 1985.

Words of the Week: Cold Soak

Outlook:

Generally a nice Thanksgiving weekend is expected, with mild temperatures, perhaps record-setting, but at least several degrees warmer than normal. Increasing clouds in the north later on Saturday with a chance for mixed precipitation. Chance for showers on Sunday statwide, lingering into Monday morning in eastern sections. Continued mild temperatures into next week, but a cool trend will be evident by next weekend. A chance for rain and snow showers around the state by Wednesday, then again by the weekend.

file:///G|/1998/WeatherTalk_1998-11-27.txt[9/22/2015 3:52:10 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Nov 6, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: November Weather-good for stored grain, bad for itchy skin

The Climate Prediction Center's November outlook for colder than normal temperatures in Minnesota seems to be right on track so far. Temperatures are averaging 4 to 6 degrees colder than normal around the state.

This pattern is good for farmers who are storing large amounts of grain this winter. It is important to aerate stored grain with fans and bring the grain temperature down to 25 to 30 degrees F. The recent trend of cooler than normal temperatures and low relative humidity has helped farmers accomplish this task. This will help insure that stored grain remains mold-free and not subject to spoilage.

Conversely, the cool, dry trend in the weather has initiated the dreaded dry skin syndrome that many Minnesotans suffer from in the winter months. Cold, dry air from the outside brought into heated homes and businesses typically becomes desert-like, drying out the mouth, nostrils, and the skin. For many this produces itchy, flaky or cracked skin conditions that are a real nuisance. The University of Delaware Center for Climate Research in conjunction with Combe Inc., makers of Lanacane lotion, have developed an Itchy Dry Skin Index to help alert the public about weather conditions that will produce severe dry skin. Their web site provides both maps and tables of the index each day and also provides a weekend forecast (available on Thursdays) for major cities in the United States. It is hoped that such information will promote better skin care among those exposed to unfavorable weather conditions. Their web site is.... http://www.udel.edu/SynClim/disi1.html

MPR listener question: When do you think the ground will freeze this year?

Answer: This is one of the most highly variable features of the Minnesota climate. Locally, in the Twin Cities area, the records of soil temperature show that the ground has frozen as early as November 13 and as late as January 8, with an average date of December 8. In some years with early and heavy snow cover, the soil has remained virtually free of frost for the entire winter. Statewide, soils typically start to freeze in the far north near mid November, and do not generally freeze in the south until near Christmas time. With a colder than normal November expected, I think that soils will likely freeze a little earlier than average this year. For the Twin Cities this may be by the end of this month. However, if we get an ample snow cover, this process may be considerably delayed.

Twin Cities Almanac for November 6th:

The average MSP high temperature for this date is 47 degrees F (plus or minus 11 degrees standard deviation), while the average low is 31 degrees F (plus or minus 9 degrees standard deviation).

MSP Local Records for November 6th:

MSP weather records for this date include: highest daily maximum temperature of 73 degrees F in 1893; lowest daily maximum temperature of 14 degrees F in 1991; lowest daily minimum temperature of 0 degrees F in 1991; highest daily minimum temperature of 53 degrees F in 1975; record rainfall of 1.35 inches in 1918 and record snowfall of 1.6 inches in 1933. There have been three measurable snowfalls on this date since 1948. Maximum snow depth has been 20 inches in 1991 and the worst windchill conditions were -35 degrees F readings in the early morning of 1991.

Average dew point for November 6th is 29 degrees F, with a maximum of 56 degrees F and a minimum of 1 degrees F.

All-time state records for November 6th:

Scanning the state climatic data base: the all-time high for this date is 79 degrees F at Clearwater (Wright County) in 1893 and at Montevideo (Chippewa County) in 1934; he all-time low is -16 degrees F at Moose Lake (Carlton County) in 1951.

Word of the Week: Fair weather

This term is commonly used to refer to visibly pleasant though not necessarily comfortable weather conditions. It is a purely subjective description and may be used with respect to what is normal or average for a particular location and time of year. When the National Weather Service includes this term in their forecasts it is supposed to satisfy some if not all of the following criteria: no precipitation expected; less than 0.4 sky cover of low clouds; very good visibility; and absence of any strong winds. The use of the term often has little regard for air temperature, so that a very warm or cold day may still be referred to as a fair weather day.

Outlook:

The pattern continues to favor below normal temperatures, with chances for precipitation, rain or snow, over the weekend and much of next week. To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Dec 4, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Experimental Winter Weather Severity Index

For years the National Weather Service has issued winter weather advisories, watches and warnings each with associated or implied criteria concerning the expected weather conditions produced by a winter storm. This year the National Weather Service Forecast Office in Cheyenne, WY is experimenting with a new Winter Weather Severity Index (WWSI) which may eventually take the place of the winter advisories, watches and warnings. It is a five category index for the severity of winter storms, much like the indices used for tornadoes (Fujita Scale) and Hurricanes (Saffir-Simpson Scale). When a WWSI category 1, 2, or 3 level storm is forecast, a winter weather advisory will be issued, while a forecast for WWSI storms of category 4 or 5 level will call for the issuance of a winter weather warning.

Some characteristics of each WWSI category are listed below..

WWSI 1. Minor inconvenience. Occurrence of winter elements (snow, cold, etc) that are typical. No significant exposure or travel concerns for most people.

WWSI 2. Some inconvenience. Combined elements may be an exposure concern to some who are continuously outside for extended periods. Traffic may be slowed in areas.

WWSI 3. Significant inconvenience. Direct exposure to combined weather elements for short periods of time may be dangerous and for extended periods perhaps life- threatening. On busy roads, travel may be slow, while on less traveled roads blowing and drifting snow may cause closures.

WWSI 4. Potentially life-threatening unless well prepared. Direct exposure to combined weather elements even for short periods may be life-threatening. Travel may be impossible on secondary roads, and difficult at best even on primary roads. Schools and businesses may choose to close.

WWSI 5. Life-threatening. Exposures for even short periods are deadly. White-out conditions likely. Travel of any sort may be impossible for up to 12 hours. Potential loss of service utilities.

We may expect that if the WWSI meets with approval in Wyoming this year, it may be expanded into Minnesota in the next year or two.

Twin Cities Almanac for December 4th:

The average MSP high temperature for this date is 32 degrees F (plus or minus 11 degrees standard deviation), while the average low is 16 degrees F (plus or minus 11 degrees standard deviation).

MSP Local Records for December 4th:

MSP weather records for this date include: highest daily maximum temperature of 56 degrees F in 1941; lowest daily maximum temperature of 2 degrees F in 1991; lowest daily minimum temperature of -11 degrees F in 1991; highest daily minimum temperature of 44 degrees F in 1941; record precipitation of 0.50 inches in 1960 and record snowfall of 4.2 inches in 1947. There have been fourteen measurable snowfalls on this date since 1948. Maximum snow depth has been 17 inches in 1985 and 1991; the worst windchill conditions were -39 degrees F in 1991.

Average dew point for December 4th is 19 degrees F, with a maximum of 49 degrees F and a minimum of -17 degrees F.

All-time state records for December 4th:

Scanning the state climatic data base: the all-time high for this date is 61 degrees F at Winona (Winona County) in 1951 and again in 1962; the all-time low is -30 degrees F at Bigfork (Itasca County) in 1964 and at Tower (St Louis County) in 1972.

Words of the Week: Afterheat and Aftersummer

These are very old terms used to refer to the warm pleasant days in the late autumn (at or after Indian Summer). It was thought that the residual heat of summer stored in the ground was released under sunny skies and helped produce temperatures that were well above normal for the late autumn. Though the soil does indeed accumulate and store heat during the summer months, periods of late autumn warmth are more often attributed to advection - the regional-scale transport of heat carried in the surface winds from one area to another. Temperatures which reach 10 to 20 degrees above normal this time of year cannot be generated locally by the low sun beating down on the Earth or by heat released from the ground.

Outlook:

Generally temperatures trending downward compared to late. Some scattered rain and snow showers are possible with a storm system over the weekend. Continued chances for snow up north during next week.

To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Dec 4, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Experimental Winter Weather Severity Index

Some characteristics of each WWSI category are listed below..

WWSI 1. Minor inconvenience. Occurrence of winter elements (snow, cold, etc) that are typical. No significant exposure or travel concerns for most people.

WWSI 2. Some inconvenience. Combined elements may be an exposure concern to some who are continuously outside for extended periods. Traffic may be slowed in areas.

WWSI 5. Life-threatening. Exposures for even short periods are deadly. White-out conditions likely. Travel of any sort may be impossible for up to 12 hours. Potential loss of service utilities.

file:///G|/1998/WeatherTalk_1998-12-04.txt[9/22/2015 3:52:10 PM] We may expect that if the WWSI meets with approval in Wyoming this year, it may be expanded into Minnesota in the next year or two.

Twin Cities Almanac for December 4th:

The average MSP high temperature for this date is 32 degrees F (plus or minus 11 degrees standard deviation), while the average low is 16 degrees F (plus or minus 11 degrees standard deviation).

MSP Local Records for December 4th:

Average dew point for December 4th is 19 degrees F, with a maximum of 49 degrees F and a minimum of -17 degrees F.

All-time state records for December 4th:

Words of the Week: Afterheat and Aftersummer

Outlook:

file:///G|/1998/WeatherTalk_1998-12-04.txt[9/22/2015 3:52:10 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Dec 11, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org). Topic: Significant weather events of 1998

Topic: Significant weather events of 1998

The National Weather Service has put together a synopsis of the most significant weather events in 1998, including Minnesota's severe weather last May. Maps showing the timing and location of these events, along with those of previous years can be found on the Internet at: http://www.nws.noaa.gov/om/disaster.htm

Topic: Where's winter?

"Building operations extended into winter, ...absence of snow cover...hardy shrubs, lawns and pastures still green...lilacs, pussy willows and other shrubs showing signs of awakening... small heating bills....complaints of poor retail sales in heavy clothing and outdoor equipment...ground and lakes still unfrozen...absence of strong winds." December 1998. NO! This description is taken from the Monthly Weather Review of early December 1913 published by the Weather Bureau.

Our weather in Minnesota has been so mild of late, it is difficult to find a historical analogy. November and December of 1913 is probably the closest, though some pioneer records suggest that 1877 may have seen a similar mild spell. Indeed, checking the past 16 days, from November 25 to December 10th in the Twin Cities, the mean daily temperature has been a remarkable 40 degrees F. This surpasses the previous record warmth for this period which occurred in 1913 when the temperature averaged 38 degrees F. Some other features of the winter of 1913-1914: a cold snap settled in by Christmas, marking it as the coldest day of the month; the first snowfall of at least 1 inch did not occur in the Twin Cities until New Year's Day (4 inches fell), and with a shortened winter the seasonal snowfall accumulation was only 22.5 inches.

With only 0.1 inches of snowfall so far, this is the latest into the snow season that the Twin Cities has seen such a paltry amount.

Topic: Lakes are slow in freezing up

Many lakes around the state have yet to show a complete ice cover (freeze up) and are pushing the record for the latest date of such an occurrence. Wolf Lake near Finland, MN (Lake County), high above the Lake Superior shoreline froze over on Monday, December 7th. This is the latest date of freeze-up for Wolf Lake. Lake Itasca froze up on Sunday, December 6th and this too is one of the latest dates ever.

Twin Cities Almanac for December 11th:

The average MSP high temperature for this date is 27 degrees F (plus or minus 12 degrees standard deviation), while the average low is 12 degrees F (plus or minus 13 degrees standard deviation).

MSP Local Records for December 11th:

MSP weather records for this date include: highest daily maximum temperature of 56 degrees F in 1913; lowest daily maximum temperature of -3 degrees F in 1962 and 1995; lowest daily minimum temperature of -14 degrees F in 1972; highest daily minimum temperature of 35 degrees F in 1965; record precipitation of 0.61 inches in 1909 and record snowfall of 5.2 inches in 1910. There have been twelve measurable snowfalls on this date since 1948. Maximum snow depth has been 16 inches in 1950; the worst windchill conditions were -59 degrees F during the nighttime in 1922.

Average dew point for December 11th is 10 degrees F, with a maximum of 49 degrees F and a minimum of -28 degrees F.

All-time state records for December 11th:

Scanning the state climatic data base: the all-time high for this date is 67 degrees F at Long Prairie (Todd County) in 1913; the all-time low is -41 degrees F at Pokegama Dam (Itasca County) in 1936.

Word of the Week: Hydropolitics

Used by resource managers, hydrologists, politicians, and to a limited extent by climatologists, this highly contemporary term refers to political negotiation and confrontation over riparian rights which may be associated with both water use and water quality. Two areas of the world where much attention is being given to hydropolitics are the Colorado River Basin in the southwestern United States and northern Mexico, and the Nile, Jordan, and Tigris-Euphrates river systems of the Middle East. The rapid growth in water consumption as more and more land is settled and developed, along with the relative scarcity of alternative water resources in these regions have contributed to somewhat of a hydropolitical crisis. In order to insure an adequate and stable water supply in the face of even normal climatic fluctuations and extrapolated population growth curves, nations and states are negotiating water-sharing treaties and agreements with more vigor than ever. We will undoubtedly be hearing much more use of the term hydropolitics in our remaining lifetime.

Outlook:

A general dry pattern will finally end by Tuesday of next week, when there will be a chance for mixed precipitation statewide. Meantime temperatures will continue to be above normal until Thursday of next week when the forecast guidance suggests that a winter storm may bring us colder air and some significant snowfall. To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Dec 11, 1998

Topic: Significant weather events of 1998

http://www.nws.noaa.gov/om/disaster.htm

Topic: Where's winter?

With only 0.1 inches of snowfall so far, this is the latest into the snow season that the Twin Cities has seen such a paltry amount.

Topic: Lakes are slow in freezing up

Many lakes around the state have yet to show a complete ice cover (freeze up) and are pushing the record for the latest date of such an occurrence. Wolf Lake near Finland, MN (Lake County),

file:///G|/1998/WeatherTalk_1998-12-11.txt[9/22/2015 3:52:10 PM] high above the Lake Superior shoreline froze over on Monday, December 7th. This is the latest date of freeze-up for Wolf Lake. Lake Itasca froze up on Sunday, December 6th and this too is the latest dates ever. Green Lake near Spicer, MN in Kandiyohi County has not yet frozen. The latest date in their record is December 16, 1959

Twin Cities Almanac for December 11th:

The average MSP high temperature for this date is 27 degrees F (plus or minus 12 degrees standard deviation), while the average low is 12 degrees F (plus or minus 13 degrees standard deviation).

MSP Local Records for December 11th:

Average dew point for December 11th is 10 degrees F, with a maximum of 49 degrees F and a minimum of -28 degrees F.

All-time state records for December 11th:

Word of the Week: Hydropolitics

Outlook:

A general dry pattern will finally end by Tuesday of next week, when there will be a chance for mixed precipitation statewide. Meantime temperatures will continue to be above normal until Thursday or Friday of next week when the forecast guidance suggests that a winter storm may bring us colder air and some significant snowfall.

file:///G|/1998/WeatherTalk_1998-12-11.txt[9/22/2015 3:52:10 PM] To: Bob Potter, Jim Bickal, John Bischoff, and Kara Fiegenschuh From: Mark Seeley Re: Suggestions for MPR's Morning Edition, Dec 18, 1998

The following will be posted as WeatherTalk on the MNONLINE web site (http://www.mnonline.org), also accessible through the Morning Edition section of MPR's web site (http://news.mpr.org).

Topic: Conditions Improving for a White Christmas in 1998

With a recent sharp change in the jet stream pattern, the northern plains will be mighty cold for the next week or more, increasing the chances for a white Christmas. A series of low pressure systems will likely bring some snowfall to the region, but also some potentially dangerous windchill conditions.

The National Climatic Data Center web site contains a report that summarizes the historical probability of a white Christmas for just about anywhere in the United States. If you are traveling this season and want to know your odds of seeing snow cover for the holidays, you can check this report which includes some maps. The web site is...... http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?WWNolos~Product~PB-009 (This is from Technical Report 95-03, entitled "White Christmas" which can be ordered online)

Topic: New Monthly and Seasonal Climate Outlooks

The new outlooks from the Climate Prediction Center suggest that temperatures may be near normal in the Great Lakes region for the month of January and balance of the winter (through March). Northern Minnesota is expected to see above normal precipitation for this period, while the southern part of the state will be near normal. These outlooks are based on historical associations with La Nina episodes and recent climate trends. A full discussion and depiction of these climate outlooks can be viewed on the Climate Prediction Center web site at.... http://nic.fb4.noaa.gov/index.html

MPR listener question: Despite the mild winter so far, it seems that more often than not we Minnesotans experience uncomfortable windchill conditions around Christmas time. I especially remember Christmas day of 1993 when windchill values were in the -35 to -45 F range. How often does the windchill factor warrant an advisory or warning from the National Weather Service on Christmas Eve and Christmas Day when people are out and about visiting friends and relatives in the Twin Cities area?

Answer: This question is a difficult one for two reasons: (1) the climatology of windchill conditions in the Twin Cities can only be derived from hourly data and the full record period is from 1891 to 1997, that's a lot of numbers; (2) the National Weather Service criteria for windchill advisories and warnings is somewhat variable and has only been used over the most recent decade or so.

The State Climatology Office has recently digitized the hourly observations for the Twin Cities, so these were used to answer the question. The National Weather Service (NWS) general criteria for the issuance of a windchill advisory are expected values of -20 F or colder and sustained winds of 10 mph or greater, while those for a windchill warning are expected values of -50 F with winds of 10 mph or greater. In Minnesota, the National Weather Service uses different criteria: -40 to -60 F for a windchill advisory and -60 F or colder for a windchill warning. The table below summarizes the climatology of windchill conditions in the Twin Cities on Christmas Eve and Christmas Day from the standpoint of meeting these NWS criteria:

Frequencies of windchill values that meet the general criteria (G) for NWS advisories and warnings and the specific criteria (MN) of the Minnesota NWS Forecast Office in Chanhassen, MN. Record period is 1891-1997. ______Windchill # of Christmas Eves # of Christmas Days Conditions ______-20 F or below (G) 36 41 -50 F or below (G) 5 6 -40 F to -60 F (MN) 11 15 -60 F or below (MN) 1 1 ______

The most extreme windchill factor on Christmas Eve was -79 F which occurred in 1983. The most extreme windchill factor on Christmas Day was -60 F which occurred in 1934. These are both in the range of values which cause exposed skin surfaces to freeze in a matter of minutes. There have been streaks of three consecutive Christmas Eves and Christmas Days when windchill factors exceeded advisory or warning criteria. These occurred in 1934-1936, 1948-1950, and 1983-1985. Perhaps the worst episode was in the 30s when windchill values on Christmas day ranged from -40 to -60 F for three consecutive years, and this on top of agricultural and economic failures across the state. What a test for the Christmas spirit!

Twin Cities Almanac for December 18th:

The average MSP high temperature for this date is 25 degrees F (plus or minus 13 degrees standard deviation), while the average low is 10 degrees F (plus or minus 14 degrees standard deviation).

MSP Local Records for December 18th:

MSP weather records for this date include: highest daily maximum temperature of 55 degrees F in 1923; lowest daily maximum temperature of -11 degrees F in 1983; lowest daily minimum temperature of -24 degrees F in 1983; highest daily minimum temperature of 34 degrees F in 1931; record precipitation of 0.28 inches in 1939 and record snowfall of 2.9 inches in 1919. There have been fourteen measurable snowfalls on this date since 1948. Maximum snow depth has been 19 inches in 1983; the worst windchill conditions were -55 degrees F at noon in 1924.

Average dew point for December 18th is 9 degrees F, with a maximum of 35 degrees F and a minimum of -26 degrees F.

All-time state records for December 18th:

Scanning the state climatic data base: the all-time high for this date is 62 degrees F at Tracy (Lyon County) and Montevideo (Chippewa County) in 1923; the all-time low is -42 degrees F at Pokegama Dam (Itasca County) in 1901.

Word of the Week: PAOBS

Yes, another scientific acronym, courtesy of the Australian Meteorological Services. The acronym stands for Australian Surface Pressure Bogus Data for the Southern Hemisphere). These are estimated surface pressure observations for the southern hemisphere derived from satellite observations, interpolated from conventional data (ship, buoy, or land surface barometer readings), or extrapolated over time from radiosonde (balloon) measurements. These data are important to an international data assimilation project, called Long Range Reanalysis, which is an attempt to reconstruct all of the surface and upper air meteorological data taken over the last 40 years. The data, originally taken from a variety of measurements and analyzed by a variety of methods, will be quality controlled, and reconstructed in a similar format for researchers to examine large scale trends and patterns in the behavior of the Earth's atmosphere. The PAOBS are important because the southern hemisphere of the Earth is dominated by oceans and has far fewer meteorological data points than the northern hemisphere. The Australian Meteorological Services has attempted to routinely characterize the pressure pattern in the southern hemisphere by making PAOB estimates over many years. Though far from perfect, PAOBs are nevertheless a consistent source of data over the decades and valued by the Reanalysis* research community. Both climatologists and meteorologists should gain a better understanding of the behavior in large scale pressure patterns of the Earth from this effort.

*Reanalysis uses available observations and the equations for conservation of energy and momentum that govern the atmosphere to interpolate in time and space meteorological conditions for areas where no observations exist. This is superior to a simple graphical interpolation because the resulting pressure fields are consistent with the physical equations that describe atmospheric fluid dynamics.

Outlook:

Much colder temperatures settling into the state beginning this weekend. A chance of snow in the north on Saturday, then again statewide Sunday through Tuesday. Low pressure systems will also bring stronger winds to the state, depressing windchill factors to -30 F or colder early next week. The magnitude of the cold may be amplified by significant snowfall accumulations in some areas of the state. Some moderation is seen by Christmas day, with temperatures perhaps returning to near normal values.

WeatherTalk for December 25, 1998

A JOYOUS HOLIDAY SEASON AND HAPPY NEW YEAR TO WEATHERTALK READERS!

Topic: Weather of Christmas Past

Snow is a very common occurrence during the Christmas Eve to New Year's Day period. Historically, some type of snowfall occurs about 85 percent of the time. Not bad if you are getting gifts like skis, snowshoes, skates, sleds, boots, etc. Approximately 43 percent of the time a snowfall has been observed on Christmas Eve and/or Christmas Day in the Twin Cities area. About 35 percent of the time a snowfall has been observed on New Year's Eve and/or New Year's Day.

All-time state records for Christmas Eve are: a high of 52 degrees F at Montevideo in 1922 and a low of -41 degrees F at Pokegama Falls in 1921. Records for Christmas Day are: a high of 56 degrees F at Winona in 1936 and a record low of -50 degrees F at Big Falls (Koochiching County) in 1933.

Other memorable Christmas holidays noted for somewhat intolerable weather were: -40 to -60 degree F windchill temperatures on Christmas Eve and Christmas Day in 1903, 1933 and 1934; twenty hours of snowfall, totaling over 11 inches on Christmas Eve and Christmas Day of 1945; and 18 inches of snow to shovel between Christmas Day and New Year's Eve in 1982.

Perhaps the most amazing Christmas weather story comes from Tom St Martin, St Paul weather historian. In 1879, following snowfalls totaling several inches just before the holiday, a strong high pressure system ushered in an arctic air mass. Christmas morning brought record cold temperatures to the Twin Cities, with -38 degrees F recorded at Signal Corps Offices in St Paul and Minneapolis and -39 degrees F at Ft Snelling. The St Paul Dispatch reported the intense cold as "being very discouraging to outdoor amusements and even interfering with visits of friendship, courtesy, charity or religion....yesterday will be long remembered as the cold Christmas...."

MPR listenr question: Since the cold snap started last Friday, how deeply have the soils frozen in the absence of much snow cover?

Soils have frozen quite rapidly. Before the cold weather arrived on December 18th, soils were barely frozen if at all. By December 22nd many soils had frozen to a depth of 7 or 8 inches. Without more snow cover, soils will continue to freeze to even greater depths. A snow cover of 4 to 6 inches would bring a halt to this freezing process by insulating the soil from further rapid heat loss.

Almanac Segment:

Twin Cities Almanac for December 25th (Christmas Day):

The average MSP high temperature for this date is 24 degrees F (plus or minus 12 degrees standard deviation), while the average low is 8 degrees F (plus or minus 14 degrees standard deviation).

MSP Local Records for December 25th:

MSP weather records for this date include: highest daily maximum temperature of 51 degrees F in 1922; lowest daily maximum temperature of -6 degrees F in 1933; lowest daily minimum temperature of -22 degrees F in 1996; highest daily minimum temperature of 36 degrees F in 1936; record precipitation of 1.35 inches in 1982 and record snowfall of 9.6 inches in 1945. There have been seventeen measurable snowfalls on this date since 1948. Maximum snow depth has been 20 inches in 1983; the worst windchill conditions were -58 degrees F at noon in 1934.

Average dew point for December 25th is 11 degrees F, with a maximum of 37 degrees F and a minimum of -25 degrees F.

All-time state records for December 25th:

Scanning the state climatic data base: the all-time high for this date is 56 degrees F at Winona (Winona County) in 1936; the all-time low is -50 degrees F at Big Falls (Koochiching County) in 1933.

Word of the Week: Seiche

This is an old Swiss term which refers to the oscillating behavior in the surface of a lake or landlocked sea. The oscillations are measurable by minor changes in depth and have a period of several minutes to several hours. This behavior is governed by a number of factors, including changes in atmospheric pressure and variations in wind.

Forecast for December 26 to January 1:

Cold temperatures will moderate Sunday and Monday, with a good chance for snow statewide. Continuing chances for snowfall during the week leading up to New Years, with temperatures fluctuating a little closer to normal.